OFFSET
7,2
COMMENTS
See A186373 for the definition of strong fixed blocks.
LINKS
Alois P. Heinz, Table of n, a(n) for n = 7..450
FORMULA
a(n) ~ 2 * n! / n^5. - Vaclav Kotesovec, Aug 29 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, May 22 2013
STATUS
approved