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 A219304 #7 Jul 23 2025 00:21:40 %S A219304 1,6,90,3334,326444,89981627,68906619754,144049729095880 %N A219304 Unchanging value maps: number of n X n binary arrays indicating the locations of corresponding elements unequal to no horizontal or vertical neighbor in a random 0..2 n X n array. %C A219304 Diagonal of A219310 %e A219304 Some solutions for n=3 %e A219304 ..0..0..0....1..0..0....1..1..1....1..0..0....0..0..0....0..1..1....1..1..1 %e A219304 ..0..0..0....0..0..1....1..1..0....1..0..0....0..0..1....0..0..1....0..0..0 %e A219304 ..0..0..0....1..0..0....1..0..0....1..1..0....0..0..1....0..1..1....0..0..0 %K A219304 nonn %O A219304 1,2 %A A219304 _R. H. Hardin_ Nov 17 2012