OFFSET
3,4
LINKS
Alois P. Heinz and Vaclav Kotesovec, Table of n, a(n) for n = 3..480 (first 100 terms from Alois P. Heinz)
FORMULA
a(n) ~ c * d^n * n!, where d = 0.63140578989563018836245602310621356272419174622597338..., c = 0.2944330707154006599431970237808940992565854768253334... . - Vaclav Kotesovec, Sep 07 2014
EXAMPLE
a(3) = 1: 123.
a(6) = 19: 124356, 125346, 126345, 134256, 135246, 136245, 145236, 146235, 156234, 234156, 235146, 236145, 245136, 246135, 256134, 345126, 346125, 356124, 456123.
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Aug 29 2013
STATUS
approved