OFFSET
4,2
COMMENTS
See A186373 for the definition of strong fixed blocks.
LINKS
Alois P. Heinz, Table of n, a(n) for n = 4..450
FORMULA
a(n) ~ n! / n^2. - Vaclav Kotesovec, Aug 29 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, May 22 2013
STATUS
approved