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

Author

Ray Chandler, Dec 15 2011

Keywords

• nonn

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.