OFFSET
0,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..42
FORMULA
a(n) = [x^(4^n)] Product_{j=1..n} 1/(1-x^j).
a(n) ~ 4^(n*(n-1)) / (n!*(n-1)!). - Vaclav Kotesovec, Jun 05 2015
EXAMPLE
a(2) = 9: 22222222, 222222211, 2222221111, 22222111111, 222211111111, 2221111111111, 22111111111111, 211111111111111, 1111111111111111.
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Feb 28 2014
STATUS
approved