login
A225964
Number of permutations of [n] having exactly 3 strong fixed blocks.
2
1, 9, 63, 419, 2868, 20932, 165662, 1432746, 13578086, 140951642, 1598792812, 19739303596, 264041415799, 3807692229035, 58907522237037, 973166134330293, 17094936849558000, 318092941562300736, 6248389843759774380, 129180041710223480596, 2803277432655658573548
OFFSET
7,2
COMMENTS
See A186373 for the definition of strong fixed blocks.
LINKS
FORMULA
a(n) ~ 2 * n! / n^5. - Vaclav Kotesovec, Aug 29 2014
CROSSREFS
Column k=3 of A186373.
Sequence in context: A230547 A339786 A201885 * A037508 A037691 A206816
KEYWORD
nonn
AUTHOR
Alois P. Heinz, May 22 2013
STATUS
approved