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.
%I A331639 #8 Oct 15 2024 17:42:24
%S A331639 1,2,2,8,2,95,2,1062,2651,17667,2,946585,2,10422801,126470568,
%T A331639 555727036,2,61345560608,2,1559456567421,28383861400820,
%U A331639 19815939349521,2,30118264353296169,8755909495925859,49334805652369611,21097628287362414244,98053701052228556867,2,27303813269345643163251
%N A331639 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 A331639 The condition that the columns be in decreasing order is equivalent to considering nonequivalent matrices with distinct columns up to permutation of columns.
%H A331639 Andrew Howroyd, <a href="/A331639/b331639.txt">Table of n, a(n) for n = 1..200</a>
%F A331639 a(n) = Sum_{d|n} A331277(n/d, d).
%F A331639 a(p) = 2 for prime p.
%Y A331639 Cf. A331277, A331638.
%K A331639 nonn
%O A331639 1,2
%A A331639 _Andrew Howroyd_, Jan 23 2020