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Number of partitions of 4^n into parts that are at most n.
2

%I #7 Jun 05 2015 16:56:29

%S 0,1,9,374,123464,393073019,13515852419746,5357744226076852121,

%T 25600195480450832892945051,1525225328241455762364837330772150,

%U 1164060788951887659290296574533366111395142,11633609031659470387047660421170953987903118055988725

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

%H Alois P. Heinz, <a href="/A238561/b238561.txt">Table of n, a(n) for n = 0..42</a>

%F a(n) = [x^(4^n)] Product_{j=1..n} 1/(1-x^j).

%F a(n) ~ 4^(n*(n-1)) / (n!*(n-1)!). - _Vaclav Kotesovec_, Jun 05 2015

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

%Y Column k=4 of A238010.

%K nonn

%O 0,3

%A _Alois P. Heinz_, Feb 28 2014