OFFSET
19,1
LINKS
Alois P. Heinz, Table of n, a(n) for n = 19..160
FORMULA
a(n) ~ c * (3*sqrt(3)/(2*Pi))^n * n! * n^6, where c = 0.000003054026651631929902... = c0 * (c0-1)^6 / (3^6 * 6!), and c0 = (1 + exp(Pi/sqrt(3))) * sqrt(3) / (2*Pi). - Vaclav Kotesovec, Aug 26 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Aug 20 2014
STATUS
approved