%N Number of nonequivalent n X n binary matrices with 3 ones in every row and column up to permutation of rows.
%C Number of factorizations of m^3 into n factors, where m is a product of exactly n distinct primes and each factor is a product of 3 distinct primes.
%H Andrew Howroyd, <a href="/A333899/b333899.txt">Table of n, a(n) for n = 0..100</a>
%Y Column k=3 of A260340.
%Y Cf. A254243.
%A _Andrew Howroyd_, Apr 18 2020