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 A284106 #6 Apr 06 2020 00:30:53 %S A284106 1,4,25,5896,905327,3514396333,12336109217951,635264284970617848, %T A284106 46214926085757662096414 %N A284106 Number of n X n 0..1 arrays with the number of 1's king-move adjacent to some 0 equal to the number of 0's adjacent to some 1, with top left element zero. %C A284106 Diagonal of A284113. %e A284106 Some solutions for n=4 %e A284106 ..0..0..0..1. .0..0..1..1. .0..1..0..1. .0..1..1..0. .0..1..1..0 %e A284106 ..1..0..0..1. .1..1..1..1. .0..0..1..1. .1..1..1..0. .1..1..0..1 %e A284106 ..1..1..0..0. .0..0..1..1. .0..0..1..0. .1..0..1..0. .1..0..0..0 %e A284106 ..1..0..1..1. .1..0..0..0. .1..1..1..0. .1..0..0..0. .0..0..1..1 %Y A284106 Cf. A284113. %K A284106 nonn %O A284106 1,2 %A A284106 _R. H. Hardin_, Mar 20 2017