A202230 Number of permutations avoiding the consecutive pattern 42531.

1, 2, 6, 24, 119, 708, 4914, 38982, 347873, 3449332, 37621965, 447648482, 5770250935, 80100822074, 1191358479790, 18900647287550, 318595643201902, 5686258136269396, 107125880782919395, 2124411456922993308, 44235624533456911964, 964959480961869203870

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 42531. It is the same as the number of permutations which avoid 13524, 24135 or 53142.

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.