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 A331641 #7 Jan 31 2020 14:47:37 %S A331641 1,0,0,1104,413088,329520720,491236986720,1181472603447024, %T A331641 4293813878010363168,22458802092186671702160, %U A331641 162578056150830848930694240,1578225306620809383358117044144,20018143307386606584084592083087648,324613983359213454501611571669979410000 %N A331641 Number of binary matrices with n columns and any number of distinct nonzero rows with 3 ones in every column. %H A331641 Andrew Howroyd, <a href="/A331641/b331641.txt">Table of n, a(n) for n = 0..100</a> %Y A331641 Row n=3 of A331567. %Y A331641 Cf. A331640. %K A331641 nonn %O A331641 0,4 %A A331641 _Andrew Howroyd_, Jan 23 2020