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 A284765 #6 Apr 05 2020 21:33:38 %S A284765 0,4,14,52,206,772,2896,10996,41862,159836,612572,2354880,9076852, %T A284765 35073264,135823868,527012084,2048410070,7974173484,31085538148, %U A284765 121332433984,474123211448,1854631573500,7261693567782,28457603057044 %N A284765 Number of n X 2 0..1 arrays with the number of 1's horizontally or vertically adjacent to some 0 one less than the number of 0's adjacent to some 1. %C A284765 Column 2 of A284771. %H A284765 R. H. Hardin, <a href="/A284765/b284765.txt">Table of n, a(n) for n = 1..210</a> %e A284765 Some solutions for n=4 %e A284765 ..0..1. .0..0. .0..1. .0..0. .0..1. .1..0. .1..0. .1..0. .1..1. .0..1 %e A284765 ..0..0. .0..0. .0..0. .1..0. .1..0. .1..0. .0..1. .0..1. .0..0. .0..0 %e A284765 ..0..0. .0..1. .1..0. .0..0. .1..0. .0..0. .0..0. .1..0. .0..0. .0..1 %e A284765 ..1..1. .1..0. .1..1. .1..1. .0..0. .1..0. .0..1. .0..0. .0..1. .1..0 %Y A284765 Cf. A284771. %K A284765 nonn %O A284765 1,2 %A A284765 _R. H. Hardin_, Apr 02 2017