F1234 swMATH ID: 19254 Software Authors: Brian Nakamura; Doron Zeilberger Description: One of the most challenging problems in enumerative combinatorics is to count Wilf classes, where you are given a pattern, or set of patterns, and you are asked to find a “formula”, or at least an efficient algorithm, that inputs a positive integer n and outputs the number of permutations avoiding that pattern. F1234, Also to enumerate permutations containing exactly r occurrences of the pattern 1234 for r=0,1,2,3, ... but made more efficient for small r, Homepage: http://www.math.rutgers.edu/~zeilberg/mamarim/mamarimhtml/Gwilf.html Dependencies: Maple Related Software: F12345; P123456; P12345; P1234; F123; P123; OEIS; SMCper; MahonianStat; HolonomicFunctions Cited in: 4 Publications all top 5 Cited by 6 Authors 3 Nakamura, Brian 2 Zeilberger, Doron 1 Janson, Svante 1 Johansson, Fredrik 1 Mansour, Toufik 1 Shattuck, Mark A. Cited in 3 Serials 2 Advances in Applied Mathematics 1 Discrete Mathematics and Theoretical Computer Science. DMTCS 1 Journal of Combinatorics Cited in 3 Fields 3 Combinatorics (05-XX) 1 Difference and functional equations (39-XX) 1 Computer science (68-XX) Citations by Year