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 A297549 #4 Dec 31 2017 15:07:51 %S A297549 1,31,2050,13248,94647,3015179,67372651,916902295,14467301940, %T A297549 290169660945,5329084696567,89381913856892,1564002749882255, %U A297549 28438920688062707,506516973635082252,8886666042271930829 %N A297549 Number of 6Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2 or 3 neighboring 1s. %C A297549 Row 6 of A297544. %H A297549 R. H. Hardin, <a href="/A297549/b297549.txt">Table of n, a(n) for n = 1..210</a> %e A297549 Some solutions for n=5 %e A297549 ..0..1..1..0..0. .0..1..0..0..0. .0..0..1..1..0. .0..0..1..1..0 %e A297549 ..0..0..1..1..0. .1..1..1..0..0. .0..1..1..0..0. .0..1..1..0..0 %e A297549 ..1..1..0..0..0. .0..1..0..0..0. .0..0..1..1..0. .0..1..1..0..0 %e A297549 ..0..1..1..0..0. .1..1..0..0..0. .0..0..0..1..0. .1..0..0..0..0 %e A297549 ..0..0..1..0..0. .1..1..1..0..0. .0..0..0..1..1. .0..1..0..1..1 %e A297549 ..0..1..1..1..0. .0..0..0..0..0. .0..0..1..1..0. .0..0..1..1..1 %Y A297549 Cf. A297544. %K A297549 nonn %O A297549 1,2 %A A297549 _R. H. Hardin_, Dec 31 2017