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 A218758 #7 Jul 23 2025 00:03:25 %S A218758 1,6,90,2942,280850,70915451,48186998294,87678602579068 %N A218758 Unmatched value maps: number of n X n binary arrays indicating the locations of corresponding elements not equal to any horizontal or vertical neighbor in a random 0..1 n X n array. %C A218758 Diagonal of A218765 %e A218758 Some solutions for n=3 %e A218758 ..1..0..0....1..1..0....1..0..0....0..0..1....1..1..0....1..1..1....0..0..1 %e A218758 ..1..1..0....1..0..0....0..0..0....0..1..1....0..0..0....1..0..1....0..0..1 %e A218758 ..1..0..0....0..0..0....0..1..0....0..0..1....0..0..1....0..0..0....0..1..1 %K A218758 nonn %O A218758 1,2 %A A218758 _R. H. Hardin_ Nov 05 2012