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Cycles in Graphs of Large Chromatic Number ★★

Author(s): Brewster; McGuinness; Moore; Noel

Conjecture   If $ \chi(G)>k $, then $ G $ contains at least $ \frac{(k+1)(k-1)!}{2} $ cycles of length $ 0\bmod k $.

Keywords: chromatic number; cycles

Oriented chromatic number of planar graphs ★★

Author(s):

An oriented colouring of an oriented graph is assignment $ c $ of colours to the vertices such that no two arcs receive ordered pairs of colours $ (c_1,c_2) $ and $ (c_2,c_1) $. It is equivalent to a homomorphism of the digraph onto some tournament of order $ k $.

Problem   What is the maximal possible oriented chromatic number of an oriented planar graph?

Keywords: oriented coloring; oriented graph; planar graph

List colorings of edge-critical graphs ★★

Author(s): Mohar

Conjecture   Suppose that $ G $ is a $ \Delta $-edge-critical graph. Suppose that for each edge $ e $ of $ G $, there is a list $ L(e) $ of $ \Delta $ colors. Then $ G $ is $ L $-edge-colorable unless all lists are equal to each other.

Keywords: edge-coloring; list coloring

The 3n+1 conjecture ★★★

Author(s): Collatz

Conjecture   Let $ f(n) = 3n+1 $ if $ n $ is odd and $ \frac{n}{2} $ if $ n $ is even. Let $ f(1) = 1 $. Assume we start with some number $ n $ and repeatedly take the $ f $ of the current number. Prove that no matter what the initial number is we eventually reach $ 1 $.

Keywords: integer sequence

A nowhere-zero point in a linear mapping ★★★

Author(s): Jaeger

Conjecture   If $ {\mathbb F} $ is a finite field with at least 4 elements and $ A $ is an invertible $ n \times n $ matrix with entries in $ {\mathbb F} $, then there are column vectors $ x,y \in {\mathbb F}^n $ which have no coordinates equal to zero such that $ Ax=y $.

Keywords: invertible; nowhere-zero flow

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Author(s):

Genshin Impact Generator Cheats without verification (Free)

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Goldberg's conjecture ★★★

Author(s): Goldberg

The overfull parameter is defined as follows: \[ w(G) = \max_{H \subseteq G} \left\lceil \frac{ |E(H)| }{ \lfloor \tfrac{1}{2} |V(H)| \rfloor} \right\rceil. \]

Conjecture   Every graph $ G $ satisfies $ \chi'(G) \le \max\{ \Delta(G) + 1, w(G) \} $.

Keywords: edge-coloring; multigraph

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Free Bloons TD Battles Energy Medal Money Cheats Pro Apk 2024 (Android Ios)

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Covering powers of cycles with equivalence subgraphs

Author(s):

Conjecture   Given $ k $ and $ n $, the graph $ C_{n}^k $ has equivalence covering number $ \Omega(k) $.

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Erdös-Szekeres conjecture ★★★

Author(s): Erdos; Szekeres

Conjecture   Every set of $ 2^{n-2} + 1 $ points in the plane in general position contains a subset of $ n $ points which form a convex $ n $-gon.

Keywords: combinatorial geometry; Convex Polygons; ramsey theory

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Jurassic Park Builder Cheats Generator 2024 No Human Verification (Brand New)

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Idle Miner Tycoon Cheats Generator 2024 Free No Verification (New.updated) ★★

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Idle Miner Tycoon Cheats Generator 2024 Free No Verification (New.updated)

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Good Edge Labelings ★★

Author(s): Araújo; Cohen; Giroire; Havet

Question   What is the maximum edge density of a graph which has a good edge labeling?

We say that a graph is good-edge-labeling critical, if it has no good edge labeling, but every proper subgraph has a good edge labeling.

Conjecture   For every $ c<4 $, there is only a finite number of good-edge-labeling critical graphs with average degree less than $ c $.

Keywords: good edge labeling, edge labeling

Grunbaum's Conjecture ★★★

Author(s): Grunbaum

Conjecture   If $ G $ is a simple loopless triangulation of an orientable surface, then the dual of $ G $ is 3-edge-colorable.

Keywords: coloring; surface

Highly arc transitive two ended digraphs ★★

Author(s): Cameron; Praeger; Wormald

Conjecture   If $ G $ is a highly arc transitive digraph with two ends, then every tile of $ G $ is a disjoint union of complete bipartite graphs.

Keywords: arc transitive; digraph; infinite graph

Exponential Algorithms for Knapsack ★★

Author(s): Lipton

Conjecture  

The famous 0-1 Knapsack problem is: Given $ a_{1},a_{2},\dots,a_{n} $ and $ b $ integers, determine whether or not there are $ 0-1 $ values $ x_{1},x_{2},\dots,x_{n} $ so that $$ \sum_{i=1}^{n} a_{i}x_{i} = b.$$ The best known worst-case algorithm runs in time $ 2^{n/2} $ times a polynomial in $ n $. Is there an algorithm that runs in time $ 2^{n/3} $?

Keywords: Algorithm construction; Exponential-time algorithm; Knapsack

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Coin Master Spins Coins Cheats 2024 No Human Verification (Real)

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New-mathod! Free Bloons TD Battles Energy Medal Money Cheats 2024 (No Human Verification) ★★

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New-mathod! Free Bloons TD Battles Energy Medal Money Cheats 2024 (No Human Verification)

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Which compact boundaryless 3-manifolds embed smoothly in the 4-sphere? ★★★

Author(s): Kirby

Problem   Determine a computable set of invariants that allow one to determine, given a compact boundaryless 3-manifold, whether or not it embeds smoothly in the 4-sphere. This should include a constructive procedure to find an embedding if the manifold is embeddable.

Keywords: 3-manifold; 4-sphere; embedding

Working Generator Pokemon Go Pokecoins Cheats Android Ios 2024 (HOT) ★★

Author(s):

Working Generator Pokemon Go Pokecoins Cheats Android Ios 2024 (HOT)

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Simpsons Tapped Out Cheats Generator Unlimited Cheats Generator (New 2024) ★★

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Simpsons Tapped Out Cheats Generator Unlimited Cheats Generator (New 2024)

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Coloring the union of degenerate graphs ★★

Author(s): Tarsi

Conjecture   The union of a $ 1 $-degenerate graph (a forest) and a $ 2 $-degenerate graph is $ 5 $-colourable.

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3-flow conjecture ★★★

Author(s): Tutte

Conjecture   Every 4-edge-connected graph has a nowhere-zero 3-flow.

Keywords: nowhere-zero flow

Cooking Fever Cheats Generator Free 2024 in 5 minutes (New Cheats Generator Cooking Fever) ★★

Author(s):

Cooking Fever Cheats Generator Free 2024 in 5 minutes (New Cheats Generator Cooking Fever)

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Cooking Fever Cheats Generator Latest Version 2024 For Free (WORKING Generator) ★★

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Cooking Fever Cheats Generator Latest Version 2024 For Free (WORKING Generator)

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Partitionning a tournament into k-strongly connected subtournaments. ★★

Author(s): Thomassen

Problem   Let $ k_1, \dots , k_p $ be positve integer Does there exists an integer $ g(k_1, \dots , k_p) $ such that every $ g(k_1, \dots , k_p) $-strong tournament $ T $ admits a partition $ (V_1\dots , V_p) $ of its vertex set such that the subtournament induced by $ V_i $ is a non-trivial $ k_i $-strong for all $ 1\leq i\leq p $.

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Number of Cliques in Minor-Closed Classes ★★

Author(s): Wood

Question   Is there a constant $ c $ such that every $ n $-vertex $ K_t $-minor-free graph has at most $ c^tn $ cliques?

Keywords: clique; graph; minor

Match Masters Free Coins Cheats 2024 (LEGIT) ★★

Author(s):

Match Masters Free Coins Cheats 2024 (LEGIT)

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Chords of longest cycles ★★★

Author(s): Thomassen

Conjecture   If $ G $ is a 3-connected graph, every longest cycle in $ G $ has a chord.

Keywords: chord; connectivity; cycle

Partition of a cubic 3-connected graphs into paths of length 2. ★★

Author(s): Kelmans

Problem   Does every $ 3 $-connected cubic graph on $ 3k $ vertices admit a partition into $ k $ paths of length $ 2 $?

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Free Call Of Duty Mobile Cheats Generator No Human Verification No Survey (Unused) ★★

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Free Call Of Duty Mobile Cheats Generator No Human Verification No Survey (Unused)

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Cooking Fever Cheats Generator Unlimited Cheats Generator (No Human Verification) ★★

Author(s):

Cooking Fever Cheats Generator Unlimited Cheats Generator (No Human Verification)

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Are there an infinite number of lucky primes?

Author(s): Lazarus: Gardiner: Metropolis; Ulam

Conjecture   If every second positive integer except 2 is remaining, then every third remaining integer except 3, then every fourth remaining integer etc. , an infinite number of the remaining integers are prime.

Keywords: lucky; prime; seive

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Author(s):

Match Masters Coins Cheats 2024 Update (FREE!!)

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Monochromatic reachability in arc-colored digraphs ★★★

Author(s): Sands; Sauer; Woodrow

Conjecture   For every $ k $, there exists an integer $ f(k) $ such that if $ D $ is a digraph whose arcs are colored with $ k $ colors, then $ D $ has a $ S $ set which is the union of $ f(k) $ stables sets so that every vertex has a monochromatic path to some vertex in $ S $.

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Frobenius number of four or more integers ★★

Author(s):

Problem   Find an explicit formula for Frobenius number $ g(a_1, a_2, \dots, a_n) $ of co-prime positive integers $ a_1, a_2, \dots, a_n $ for $ n\geq 4 $.

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The Crossing Number of the Complete Graph ★★★

Author(s):

The crossing number $ cr(G) $ of $ G $ is the minimum number of crossings in all drawings of $ G $ in the plane.

Conjecture   $ \displaystyle cr(K_n) =   \frac 14 \floor{\frac n2} \floor{\frac{n-1}2} \floor{\frac{n-2}2} \floor{\frac{n-3}2} $

Keywords: complete graph; crossing number

Match Masters Free Coins Cheats 2024 (FREE!) ★★

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Match Masters Free Coins Cheats 2024 (FREE!)

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World of Warships Cheats Generator Free Strategy 2024 (The Legit Method) ★★

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World of Warships Cheats Generator Free Strategy 2024 (The Legit Method)

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World of Warships Cheats Generator Link 2024 (Cheats Generator that work) ★★

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World of Warships Cheats Generator Link 2024 (Cheats Generator that work)

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Divisibility of central binomial coefficients ★★

Author(s): Graham

Problem  (1)   Prove that there exist infinitely many positive integers $ n $ such that $$\gcd({2n\choose n}, 3\cdot 5\cdot 7) = 1.$$
Problem  (2)   Prove that there exists only a finite number of positive integers $ n $ such that $$\gcd({2n\choose n}, 3\cdot 5\cdot 7\cdot 11) = 1.$$

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eFootball 2023 Cheats Generator Unlimited IOS Android No Survey 2024 (Reedem Today) ★★

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eFootball 2023 Cheats Generator Unlimited IOS Android No Survey 2024 (Reedem Today)

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Rainbow Six Siege Cheats Generator Unlimited R6 No Jailbreak (Premium Orginal Generator) ★★

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Rainbow Six Siege Cheats Generator Unlimited R6 No Jailbreak (Premium Orginal Generator)

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Giuga's Conjecture on Primality ★★

Author(s): Giuseppe Giuga

Conjecture   $ p $ is a prime iff $ ~\displaystyle \sum_{i=1}^{p-1} i^{p-1} \equiv -1 \pmod p $

Keywords: primality

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Simpsons Tapped Out Cheats Generator Unlimited Cheats Generator IOS Android 2024 (get codes)

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Yu Gi Oh Duel Links Cheats Generator 2024 (safe and working)

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Real Racing 3 Cheats Generator Working 2024 (Real Racing 3 Generator)

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Direct proof of a theorem about compact funcoids ★★

Author(s): Porton

Conjecture   Let $ f $ is a $ T_1 $-separable (the same as $ T_2 $ for symmetric transitive) compact funcoid and $ g $ is a uniform space (reflexive, symmetric, and transitive endoreloid) such that $ ( \mathsf{\tmop{FCD}}) g = f $. Then $ g = \langle f \times f \rangle^{\ast} \Delta $.

The main purpose here is to find a direct proof of this conjecture. It seems that this conjecture can be derived from the well known theorem about existence of exactly one uniformity on a compact set. But that would be what I call an indirect proof, we need a direct proof instead.

The direct proof may be constructed by correcting all errors an omissions in this draft article.

Direct proof could be better because with it we would get a little more general statement like this:

Conjecture   Let $ f $ be a $ T_1 $-separable compact reflexive symmetric funcoid and $ g $ be a reloid such that
    \item $ ( \mathsf{\tmop{FCD}}) g = f $; \item $ g \circ g^{- 1} \sqsubseteq g $.

Then $ g = \langle f \times f \rangle^{\ast} \Delta $.

Keywords: compact space; compact topology; funcoid; reloid; uniform space; uniformity

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Cooking Fever Cheats Generator Android Ios No Survey 2024 (NEW)

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Working Dragon Ball Legends Cheats Generator Online (No Survey)

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