2015/05/25 by Scott Garrabrant, Garrabrant, Scott, Igor Pak +1 · 1 citation
Computer Science · Mathematics · #semigroups and automata theory #Cellular Automata and Applications #Advanced Combinatorial Mathematics
paper · pdf · doi:10.48550/arxiv.1505.06508
Let F ⊂ Sk be a finite set of permutations and let Cn(F) denote the number of permutations σ in Sn avoiding the set of patterns F. The Noonan-Zeilberger conjecture states that the sequence Cn(F) is P-recursive. We use Computability Theory to disprove this conjecture.