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 A318337 #7 Apr 14 2020 21:32:10 %S A318337 1,6,20,67,393,4133,86487,3590263,285034170,43174729552, %T A318337 12383193287684,6712873423988949,6871475875643572553, %U A318337 13272675681120501977922,48367944991570243925176462,332490278773637201581189154380 %N A318337 Number of n X n 0..1 arrays with every element unequal to 0, 1, 2 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. %C A318337 Diagonal of A318343. %H A318337 R. H. Hardin, <a href="/A318337/b318337.txt">Table of n, a(n) for n = 1..17</a> %e A318337 Some solutions for n=5 %e A318337 ..0..1..1..1..1. .0..0..0..0..0. .0..0..0..0..0. .0..1..1..1..1 %e A318337 ..0..1..1..1..1. .0..1..0..0..0. .0..0..0..0..0. .1..1..1..1..0 %e A318337 ..0..1..1..1..1. .0..0..0..0..0. .0..0..0..0..0. .1..1..1..0..0 %e A318337 ..0..1..1..1..1. .0..0..0..0..0. .0..0..1..0..0. .1..1..0..0..0 %e A318337 ..0..1..1..1..0. .1..1..1..1..1. .0..0..0..0..0. .1..0..0..0..0 %Y A318337 Cf. A318343. %K A318337 nonn %O A318337 1,2 %A A318337 _R. H. Hardin_, Aug 24 2018