A238561 Number of partitions of 4^n into parts that are at most n.

0, 1, 9, 374, 123464, 393073019, 13515852419746, 5357744226076852121, 25600195480450832892945051, 1525225328241455762364837330772150, 1164060788951887659290296574533366111395142, 11633609031659470387047660421170953987903118055988725

Offset: 0

Author

Alois P. Heinz, Feb 28 2014

Keywords

• nonn

Examples

			a(2) = 9: 22222222, 222222211, 2222221111, 22222111111, 222211111111, 2221111111111, 22111111111111, 211111111111111, 1111111111111111.
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..42

Crossrefs

Column k=4 of A238010.

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