%I #9 Apr 05 2017 11:55:07
%S 1,1,1,13,401,93151,88853970,482430702570
%N Number of partitions of n copies of n^2 into distinct parts.
%F a(n) = 1/n! * [Product_{i=1..n} x_i^(n^2)] Product_{j>0} (1+Sum_{i=1..n} x_i^j).
%F a(n) = A258280(n^2,n).
%e a(3) = 13: [9;8,1;7,2], [9;8,1;6,3], [9;8,1;5,4], [9;8,1;4,3,2], [9;7,2;6,3], [9;7,2;5,4], [9;7,2;5,3,1], [9;6,3;5,4], [9;5,4;6,2,1], [8,1;7,2;6,3], [8,1;7,2;5,4], [8,1;6,3;5,4], [7,2;6,3;5,4].
%Y Cf. A258280.
%K nonn,more
%O 0,4
%A _Alois P. Heinz_, Apr 03 2017