A202218 Number of permutations avoiding the consecutive pattern 32451.

1, 2, 6, 24, 119, 708, 4914, 38977, 347793, 3448182, 37605545, 447406214, 5766525727, 80040747361, 1190340631290, 18882526564227, 318256944873984, 5679619717431613, 106989639176572571, 2121488012937187849, 44170136425049025574, 963430265253564585315

Offset

1,2

Comments

a(n) is the number of permutations on [n] that avoid the consecutive pattern 32451. It is the same as the number of permutations which avoid 15423, 34215 or 51243.

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: A202222 A202214 A202215 * A202219 A202223 A202220

Adjacent sequences: A202215 A202216 A202217 * A202219 A202220 A202221

Keyword

nonn

Author

Ray Chandler, Dec 15 2011

Status

approved