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Number of binary matrices with nonzero rows, a total of n ones and distinct columns each with the same number of ones and columns in decreasing lexicographic order.
3

%I #8 Oct 15 2024 17:42:24

%S 1,2,2,8,2,95,2,1062,2651,17667,2,946585,2,10422801,126470568,

%T 555727036,2,61345560608,2,1559456567421,28383861400820,

%U 19815939349521,2,30118264353296169,8755909495925859,49334805652369611,21097628287362414244,98053701052228556867,2,27303813269345643163251

%N Number of binary matrices with nonzero rows, a total of n ones and distinct columns each with the same number of ones and columns in decreasing lexicographic order.

%C The condition that the columns be in decreasing order is equivalent to considering nonequivalent matrices with distinct columns up to permutation of columns.

%H Andrew Howroyd, <a href="/A331639/b331639.txt">Table of n, a(n) for n = 1..200</a>

%F a(n) = Sum_{d|n} A331277(n/d, d).

%F a(p) = 2 for prime p.

%Y Cf. A331277, A331638.

%K nonn

%O 1,2

%A _Andrew Howroyd_, Jan 23 2020