A202233 Number of permutations avoiding the consecutive pattern 45231.

1, 2, 6, 24, 119, 708, 4915, 38992, 347980, 3450572, 37637545, 447857256, 5773243451, 80146549212, 1192100892680, 18913413488544, 318827489139059, 5690693361661052, 107215038571876213, 2126290615269312536, 44277066284532913066, 965913951460006237612

Offset

1,2

Comments

a(n) is the number of permutations on [n] that avoid the consecutive pattern 45231. It is the same as the number of permutations which avoid 13254, 21435 or 53412.

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: A202230 A202232 A202234 * A202235 A202236 A177523

Adjacent sequences: A202230 A202231 A202232 * A202234 A202235 A202236

Keyword

nonn

Author

Ray Chandler, Dec 15 2011

Status

approved