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A333899 Number of nonequivalent n X n binary matrices with 3 ones in every row and column up to permutation of rows. 2

%I

%S 1,0,0,1,1,22,550,16700,703297,38135272,2584332084,214050246975,

%T 21269928579625,2497135296996934,341930210261762434,

%U 54008226638062039798,9746833030828647070625,1993080976749664740373600,458405276998431265342151848,117814680468332544208002721773

%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.

%K nonn

%O 0,6

%A _Andrew Howroyd_, Apr 18 2020

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Last modified November 29 01:40 EST 2021. Contains 349416 sequences. (Running on oeis4.)