A225968 Number of permutations of [n] having exactly 7 strong fixed blocks.

1, 25, 375, 4439, 46240, 449376, 4226604, 39474916, 373382588, 3635491860, 36957484104, 397181210056, 4560293779650, 56383382731802, 754184534296262, 10926207562498862, 171119131459887864, 2885501334257214456, 52124282589435604908, 1003403354618592544692

Offset: 19

Author

Alois P. Heinz, May 22 2013

Keywords

• nonn

Comments

See A186373 for the definition of strong fixed blocks.

Links

• Alois P. Heinz, Table of n, a(n) for n = 19..460

Crossrefs

Column k=7 of A186373.

Formula

a(n) ~ 6 * n! / n^17. - Vaclav Kotesovec, Aug 29 2014