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Number of nonequivalent n-column binary matrices with 3 ones in every column and any number of distinct nonzero rows up to permutation of rows and columns.
2

%I #6 Feb 07 2020 20:49:35

%S 1,0,0,3,23,191,2203,31313

%N Number of nonequivalent n-column binary matrices with 3 ones in every column and any number of distinct nonzero rows up to permutation of rows and columns.

%e The a(3) = 3 matrices are:

%e [1, 1, 0] [1, 1, 1] [1, 1, 1]

%e [1, 0, 1] [1, 1, 0] [1, 1, 0]

%e [1, 0, 0] [1, 0, 1] [1, 0, 1]

%e [0, 1, 1] [0, 1, 0] [0, 1, 1]

%e [0, 1, 0] [0, 0, 1]

%e [0, 0, 1]

%Y Row n=3 of A331510.

%Y Cf. A331717.

%K nonn,more

%O 0,4

%A _Andrew Howroyd_, Feb 02 2020