%I #5 Jan 25 2020 02:24:07
%S 1,4,16,91,546,5094,47306,561190,7098943,103345704,1622632638,
%T 28216141886,526858348514,10659286804538,230286817182060,
%U 5319206290975993,130370767029136518,3386434807625742926,92801587319328412310,2677967917777310591454,81124837170900250181072
%N Number of nonnegative integer matrices with distinct nonzero rows, total sum n and columns with equal sums.
%F a(n) = Sum_{d|n} A331568(d/n, d).
%e The a(2) = 4 matrices are:
%e [1 0] [0 1] [1 1] [2]
%e [0 1] [1 0]
%Y Cf. A331568.
%K nonn
%O 1,2
%A _Andrew Howroyd_, Jan 24 2020