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%I #7 Jan 31 2020 14:48:06
%S 1,0,6,120,6174,449520,49686726,7455901320,1479839874414,
%T 373573957133280,117097298726892246,44596327028174342520,
%U 20287402287658565190654,10864410524883717498300240,6765647366010527963979060966,4847736403559133115838948559720
%N Number of binary matrices with n columns and any number of distinct nonzero rows with 2 ones in every column.
%H Andrew Howroyd, <a href="/A331640/b331640.txt">Table of n, a(n) for n = 0..200</a>
%e The a(2) = 6 matrices are:
%e [1 1] [1 1] [1 0] [1 0] [0 1] [0 1]
%e [1 0] [0 1] [1 1] [0 1] [1 1] [1 0]
%e [0 1] [1 0] [0 1] [1 1] [1 0] [1 1]
%Y Row n=2 of A331567.
%Y Cf. A331641.
%K nonn
%O 0,3
%A _Andrew Howroyd_, Jan 23 2020