cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A331717 Number of nonequivalent n-column binary matrices with 2 ones in every column and any number of distinct nonzero rows up to permutation of rows and columns.

This page as a plain text file.
%I A331717 #5 Feb 07 2020 20:49:28
%S A331717 1,0,1,4,12,36,124,412,1500
%N A331717 Number of nonequivalent n-column binary matrices with 2 ones in every column and any number of distinct nonzero rows up to permutation of rows and columns.
%e A331717 The a(3) = 4 matrices are:
%e A331717   [1 1 1]  [1 1 0]  [1 1 1]  [1 1 0]
%e A331717   [1 0 0]  [1 0 1]  [1 1 0]  [1 0 1]
%e A331717   [0 1 0]  [0 1 0]  [0 0 1]  [0 1 1]
%e A331717   [0 0 1]  [0 0 1]
%Y A331717 Row n=2 of A331510.
%Y A331717 Cf. A331718.
%K A331717 nonn,more
%O A331717 0,4
%A A331717 _Andrew Howroyd_, Feb 02 2020