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 A268908 #6 Apr 10 2022 14:24:19 %S A268908 0,6912,98496,1347192,17194680,214142760,2611960344,31382176824, %T A268908 372469407912,4376985056856,51011490408120,590386685589432, %U A268908 6792451934064264,77748739088317848,885979967930009496 %N A268908 Number of 5 X n 0..2 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once. %C A268908 Row 5 of A268904. %H A268908 R. H. Hardin, <a href="/A268908/b268908.txt">Table of n, a(n) for n = 1..210</a> %F A268908 Empirical: a(n) = 32*a(n-1) -384*a(n-2) +2200*a(n-3) -6494*a(n-4) +9016*a(n-5) -816*a(n-6) -14888*a(n-7) +18879*a(n-8) -5464*a(n-9) -7472*a(n-10) +8336*a(n-11) -3648*a(n-12) +768*a(n-13) -64*a(n-14) for n>18. %e A268908 Some solutions for n=3 %e A268908 ..2..2..1. .0..2..2. .2..1..2. .1..0..1. .2..1..2. .0..0..0. .2..1..0 %e A268908 ..2..0..1. .1..2..1. .2..1..0. .0..2..2. .0..2..1. .1..0..0. .2..1..0 %e A268908 ..1..2..1. .1..0..1. .0..0..1. .2..2..2. .1..2..2. .1..0..0. .2..1..0 %e A268908 ..1..0..0. .1..2..2. .1..2..2. .1..2..2. .1..2..2. .0..1..0. .2..1..2 %e A268908 ..0..0..0. .1..2..2. .1..1..0. .1..2..2. .2..2..1. .0..1..1. .0..0..0 %Y A268908 Cf. A268904. %K A268908 nonn %O A268908 1,2 %A A268908 _R. H. Hardin_, Feb 15 2016