Open Problems

Title	Author(s)	Imp.¹	Rec.²	Area » Topic » Subtopic	Posted by
Are there an infinite number of lucky primes?	Lazarus: Gardiner: Metropolis; Ulam	✭	1	Number Theory » Additive N.T.	cubola zaruka
Point sets with no empty pentagon	Wood	✭	1	Geometry	David Wood
Special Primes	George BALAN	✭	1	Number Theory	maththebalans
Covering powers of cycles with equivalence subgraphs		✭	0	Graph Theory	Andrew King
Strict inequalities for products of filters	Porton	✭	0	Topology	porton
Obstacle number of planar graphs	Alpert; Koch; Laison	✭	1	Graph Theory	Andrew King
Length of surreal product	Gonshor	✭	1	Combinatorics	Lukáš Lánský
Circular choosability of planar graphs	Mohar	✭	0	Graph Theory » Coloring » Homomorphisms	rosskang
Mixing Circular Colourings	Brewster; Noel	✭	1	Graph Theory » Coloring » Vertex coloring	Jon Noel
Melnikov's valency-variety problem	Melnikov	✭	0	Graph Theory » Coloring » Vertex coloring	asp
Weak saturation of the cube in the clique	Morrison; Noel	✭	1	Graph Theory » Extremal G.T.	Jon Noel

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