Anick-type resolutions and consecutive pattern avoidance
arXiv:1002.2761
Abstract
For permutations avoiding consecutive patterns from a given set, we present a combinatorial formula for the multiplicative inverse of the corresponding exponential generating function. The formula comes from homological algebra considerations in the same sense as the corresponding inversion formula for avoiding word patterns comes from the well known Anick's resolution.
16 pages. Preliminary version, comments are welcome