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 A293083 #6 Apr 05 2020 23:38:25 %S A293083 0,23,486,8108,126903,1955375,30064393,462569756,7127871677, %T A293083 110032675158,1701716646013,26365297553133,409178131040177, %U A293083 6360241131134572,99006293076495153,1543225051401234780,24083853470118205024 %N A293083 Number of n X 4 0..1 arrays with the number of 1's horizontally or antidiagonally adjacent to some 0 two less than the number of 0's adjacent to some 1. %C A293083 Column 4 of A293087. %H A293083 R. H. Hardin, <a href="/A293083/b293083.txt">Table of n, a(n) for n = 1..210</a> %e A293083 Some solutions for n=4 %e A293083 ..0..0..0..0. .0..1..0..0. .0..0..0..0. .1..0..0..1. .0..1..1..1 %e A293083 ..0..1..0..0. .1..0..1..0. .0..0..1..1. .1..1..0..0. .0..1..0..1 %e A293083 ..0..0..1..1. .0..0..1..0. .1..0..1..0. .0..1..0..0. .1..0..0..0 %e A293083 ..1..1..0..0. .1..0..1..1. .0..0..1..0. .0..0..1..1. .0..0..1..0 %Y A293083 Cf. A293087. %K A293083 nonn %O A293083 1,2 %A A293083 _R. H. Hardin_, Sep 30 2017