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 A285154 #6 Apr 05 2020 23:14:32 %S A285154 0,12,113,820,5773,41620,305641,2274080,17114289,129576988,987231526, %T A285154 7551235806,57992581744,446683948074,3450295188177,26710836161850, %U A285154 207217760171898,1610393410029550,12535446041119817,97715224210141008 %N A285154 Number of 3 X n 0..1 arrays with the number of 1's horizontally or antidiagonally adjacent to some 0 one less than the number of 0's adjacent to some 1. %C A285154 Row 3 of A285152. %H A285154 R. H. Hardin, <a href="/A285154/b285154.txt">Table of n, a(n) for n = 1..210</a> %e A285154 Some solutions for n=4 %e A285154 ..1..1..1..1. .0..0..1..0. .1..0..1..0. .0..1..1..0. .0..1..0..0 %e A285154 ..1..1..1..0. .1..0..1..0. .0..1..1..1. .0..0..1..1. .1..1..0..0 %e A285154 ..0..0..0..1. .0..1..1..0. .0..0..0..0. .0..1..1..0. .1..0..1..1 %Y A285154 Cf. A285152. %K A285154 nonn %O A285154 1,2 %A A285154 _R. H. Hardin_, Apr 12 2017