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 A317758 #4 Aug 06 2018 11:47:56 %S A317758 1,6,16,43,109,266,639,1529,3674,8909,21853,54252,136213,345373, %T A317758 882828,2271143,5871373,15234214,39633091,103306417,269641062, %U A317758 704462713,1841692605,4816973880,12602801545 %N A317758 Number of nXn 0..1 arrays with every element unequal to 0, 1 or 2 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. %C A317758 Diagonal of A317764. %e A317758 Some solutions for n=5 %e A317758 ..0..1..1..1..1. .0..1..1..1..1. .0..1..1..1..1. .0..0..0..0..0 %e A317758 ..1..1..1..1..1. .1..1..1..1..1. .1..1..1..1..1. .0..0..0..0..0 %e A317758 ..0..0..0..0..0. .1..1..1..1..1. .1..1..1..1..1. .0..0..0..0..0 %e A317758 ..0..0..0..0..1. .1..1..1..1..1. .1..1..1..1..0. .0..0..0..0..0 %e A317758 ..0..0..0..1..1. .0..0..0..0..0. .1..1..1..0..0. .0..0..0..0..1 %Y A317758 Cf. A317764. %K A317758 nonn %O A317758 1,2 %A A317758 _R. H. Hardin_, Aug 06 2018