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 A282784 #6 Apr 26 2020 20:39:17 %S A282784 0,0,73,1952,208559,34974844,12713143876,10031326473244, %T A282784 16844842566734425,61957626701788646084,497581272671041376917187 %N A282784 Number of n X n 0..1 arrays with no 1 equal to more than one of its king-move neighbors, with the exception of exactly one element. %C A282784 Diagonal of A282791. %e A282784 Some solutions for n=4 %e A282784 ..0..0..1..0. .1..0..0..1. .1..0..1..1. .0..1..0..1. .0..1..0..0 %e A282784 ..0..0..0..0. .0..1..0..0. .1..0..0..0. .0..1..0..0. .0..0..1..1 %e A282784 ..0..0..1..0. .1..0..0..0. .1..0..0..0. .0..0..1..0. .1..0..0..0 %e A282784 ..0..1..0..1. .0..0..0..0. .0..0..0..1. .1..0..0..0. .0..0..1..1 %Y A282784 Cf. A282791. %K A282784 nonn %O A282784 1,3 %A A282784 _R. H. Hardin_, Feb 21 2017