%I #13 Nov 02 2018 12:38:58
%S 1,1,1,2,392,3245664,6534071578530
%N Number of set partitions of [n^2] into n n-element subsets having the same sum.
%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Partition_of_a_set">Partition of a set</a>
%F a(n) = A203986(n,n).
%e a(0) = 1: empty.
%e a(1) = 1: 1.
%e a(2) = 1: 14|23.
%e a(3) = 2: 168|249|357, 159|267|348.
%Y Main diagonal of A203986.
%Y Cf. A006003, A037270, A052456, A104185, A321282.
%K nonn,more
%O 0,4
%A _Alois P. Heinz_, Oct 31 2018