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 A298889 #6 Jun 15 2020 13:57:43 %S A298889 0,1,1,11,219,2963,74725,5719782,724538480,145951109194 %N A298889 Number of n X n 0..1 arrays with every element equal to 2, 3, 5, 6 or 8 king-move adjacent elements, with upper left element zero. %C A298889 Diagonal of A298895. %e A298889 Some solutions for n=7 %e A298889 ..0..0..0..0..1..1..1. .0..0..0..1..1..1..0. .0..0..1..0..0..1..1 %e A298889 ..0..1..1..0..1..1..1. .0..1..1..0..1..0..0. .1..0..1..1..0..0..1 %e A298889 ..1..0..1..1..1..0..0. .1..0..0..1..1..1..0. .1..1..0..0..0..0..0 %e A298889 ..1..0..0..0..1..1..0. .1..0..1..1..1..1..1. .0..0..0..0..1..1..0 %e A298889 ..1..0..1..0..0..0..1. .0..1..1..1..0..0..1. .0..0..0..1..0..1..0 %e A298889 ..1..0..1..1..1..1..0. .1..0..1..0..1..1..0. .0..0..0..1..0..0..1 %e A298889 ..1..1..0..0..0..0..0. .1..1..0..1..0..0..0. .0..0..0..1..1..1..1 %Y A298889 Cf. A298895. %K A298889 nonn %O A298889 1,4 %A A298889 _R. H. Hardin_, Jan 28 2018