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 A269295 #4 Feb 21 2016 09:32:22 %S A269295 16384,34012224,26317946844,17623065834612,10908770041709316, %T A269295 6444304707617709156,3689070798270477232620,2064575194564255507198260, %U A269295 1135872003598654165478951652,616641759542150716175805966228 %N A269295 Number of 7Xn 0..3 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling three no more than once. %C A269295 Row 7 of A269289. %H A269295 R. H. Hardin, <a href="/A269295/b269295.txt">Table of n, a(n) for n = 1..210</a> %e A269295 Some solutions for n=2 %e A269295 ..0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0 %e A269295 ..0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0 %e A269295 ..2..3. .0..1. .1..1. .2..0. .2..3. .2..2. .2..0. .2..2. .2..1. .2..2 %e A269295 ..0..2. .0..0. .1..0. .3..1. .3..3. .0..1. .3..1. .0..0. .1..3. .0..0 %e A269295 ..2..0. .1..3. .1..2. .0..0. .3..1. .2..0. .1..3. .1..3. .3..2. .1..0 %e A269295 ..2..3. .3..3. .0..0. .1..1. .0..0. .2..2. .2..3. .2..2. .0..0. .3..1 %e A269295 ..1..1. .1..2. .0..0. .1..3. .1..0. .2..2. .2..2. .2..0. .2..2. .0..1 %Y A269295 Cf. A269289. %K A269295 nonn %O A269295 1,1 %A A269295 _R. H. Hardin_, Feb 21 2016