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

Author

Ray Chandler, Dec 15 2011

Keywords

• nonn

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.