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 A284454 #6 Apr 05 2020 23:01:17 %S A284454 28,0,278315,12957944,3478866516,197373621124,45913351929099, %T A284454 3020610942888634,635171432700031740,46935468157115829048, %U A284454 9070472121517777538083,735727339860385496580626 %N A284454 Number of n X 7 0..1 arrays with the number of 1's king-move adjacent to some 0 one less than the number of 0's adjacent to some 1. %C A284454 Column 7 of A284455. %H A284454 R. H. Hardin, <a href="/A284454/b284454.txt">Table of n, a(n) for n = 1..28</a> %e A284454 Some solutions for n=3 %e A284454 ..0..1..1..0..1..1..0. .0..1..0..0..0..0..1. .0..0..1..0..1..0..1 %e A284454 ..0..1..0..0..0..1..0. .0..1..1..1..0..0..1. .0..1..0..1..0..0..0 %e A284454 ..1..0..1..0..0..1..1. .0..1..1..0..0..1..1. .1..1..1..1..0..0..0 %Y A284454 Cf. A284455. %K A284454 nonn %O A284454 1,1 %A A284454 _R. H. Hardin_, Mar 27 2017