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 A293095 #6 Apr 05 2020 23:45:25 %S A293095 0,9,48,554,3334,30837,202363,1733660,12139768,99907487,729039938, %T A293095 5866737162,43944684689,349284676982,2660349798813,21006556689388, %U A293095 161738436141669,1272996087653588,9871903975910464,77596716393162478 %N A293095 Number of n X 3 0..1 arrays with the number of 1's horizontally, diagonally or antidiagonally adjacent to some 0 two less than the number of 0's adjacent to some 1. %C A293095 Column 3 of A293100. %H A293095 R. H. Hardin, <a href="/A293095/b293095.txt">Table of n, a(n) for n = 1..210</a> %e A293095 Some solutions for n=4 %e A293095 ..0..0..1. .0..0..1. .0..1..1. .1..1..0. .0..0..0. .1..0..0. .0..0..0 %e A293095 ..0..1..0. .1..1..0. .0..1..0. .1..0..0. .0..1..1. .0..1..0. .1..0..0 %e A293095 ..0..0..0. .0..0..0. .1..1..0. .0..1..0. .1..1..0. .0..0..1. .1..1..0 %e A293095 ..1..1..1. .1..1..0. .0..1..0. .0..1..0. .1..0..0. .1..1..0. .0..1..0 %Y A293095 Cf. A293100. %K A293095 nonn %O A293095 1,2 %A A293095 _R. H. Hardin_, Sep 30 2017