A202217 Number of permutations avoiding the consecutive pattern 45132.

1, 2, 6, 24, 119, 708, 4914, 38976, 347776, 3447932, 37601916, 447352224, 5765690544, 80027220448, 1190110692204, 18878422622976, 318180082610048, 5678110761876224, 106958628519952128, 2120821833862388544, 44155198873515034560, 963081167548894179456

Offset

1,2

Comments

a(n) is the number of permutations on [n] that avoid the consecutive pattern 45132. It is the same as the number of permutations which avoid 21534, 23154 or 43512.

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: A071077 A202213 A202216 * A202221 A202222 A202214

Adjacent sequences: A202214 A202215 A202216 * A202218 A202219 A202220

Keyword

nonn

Author

Ray Chandler, Dec 14 2011

Status

approved