A202225 Number of permutations avoiding the consecutive pattern 43521.

1, 2, 6, 24, 119, 708, 4914, 38980, 347837, 3448792, 37614098, 447531000, 5768428803, 80071254648, 1190855183414, 18891654561628, 318427067939961, 5682946188447440, 107057773100175102, 2122947536807150960, 44202783404925357767, 964191633859884115696

Offset

1,2

Comments

a(n) is the number of permutations on [n] that avoid the consecutive pattern 43521. It is the same as the number of permutations which avoid 12534, 23145 or 54132.

Links

Ray Chandler, Table of n, a(n) for n = 1..40

A. Baxter, B. Nakamura, and D. Zeilberger. Automatic generation of theorems and proofs on enumerating consecutive Wilf-classes

Crossrefs

Cf. A177523, A202213-A202236.

Sequence in context: A202227 A202229 A202224 * A202231 A202228 A202230

Adjacent sequences: A202222 A202223 A202224 * A202226 A202227 A202228

Keyword

nonn

Author

Ray Chandler, Dec 15 2011

Status

approved