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 A283040 #4 Feb 27 2017 08:59:51 %S A283040 12,924,30378,931844,26180826,706205768,18455711930,471954803540, %T A283040 11868995624930,294610925837548,7236339162353190,176211017312981820, %U A283040 4259949495613038410,102354621908646110164,2446336908511893682666 %N A283040 Number of nX6 0..1 arrays with no 1 equal to more than one of its horizontal and vertical neighbors, with the exception of exactly one element. %C A283040 Column 6 of A283042. %H A283040 R. H. Hardin, <a href="/A283040/b283040.txt">Table of n, a(n) for n = 1..210</a> %e A283040 Some solutions for n=3 %e A283040 ..1..0..1..1..0..1. .1..1..0..0..1..0. .0..1..0..0..0..1. .0..0..0..0..0..1 %e A283040 ..0..1..0..0..1..0. .0..1..0..0..0..1. .1..1..1..0..1..0. .1..1..0..1..0..0 %e A283040 ..0..0..0..1..1..1. .1..0..0..1..0..0. .0..1..0..0..0..1. .0..0..0..1..1..0 %Y A283040 Cf. A283042. %K A283040 nonn %O A283040 1,1 %A A283040 _R. H. Hardin_, Feb 27 2017