TY - JOUR

T1 - Enumeration of permutations avoiding a triple of 4-letter patterns is almost all done

AU - Callan, David

AU - Mansour, Toufik

AU - Shattuck, Mark

PY - 2019

Y1 - 2019

N2 - This paper basically completes a project to enumerate permutations avoiding a triple T of 4-letter patterns, in the sense of classical pattern avoidance, for every T . There are 317 symmetry classes of such triples T and previous papers have enumerated avoiders for all but 14 of them. One of these 14 is conjectured not to have an algebraic generating function. Here, we find the generating function for each of the remaining 13, and it is algebraic in each case.

AB - This paper basically completes a project to enumerate permutations avoiding a triple T of 4-letter patterns, in the sense of classical pattern avoidance, for every T . There are 317 symmetry classes of such triples T and previous papers have enumerated avoiders for all but 14 of them. One of these 14 is conjectured not to have an algebraic generating function. Here, we find the generating function for each of the remaining 13, and it is algebraic in each case.

U2 - 10.1515/puma-2015-0031

DO - 10.1515/puma-2015-0031

M3 - מאמר

SN - 1218-4586

VL - 28

SP - 14

EP - 69

JO - Pure Mathematics and Applications

JF - Pure Mathematics and Applications

IS - 1

ER -