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 A302145 #7 Apr 20 2020 00:04:51 %S A302145 1,1,4,17,289,15999,1728734,476725579,338788296901,600144995821877, %T A302145 2721126689318370799,31005436248594896441733, %U A302145 885614872309613750483721526,63247599647658758935122240950370,11261549689102506355299411976654023890 %N A302145 Number of n X n 0..1 arrays with every element equal to 0, 2, 3 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero. %C A302145 Diagonal of A302150. %H A302145 R. H. Hardin, <a href="/A302145/b302145.txt">Table of n, a(n) for n = 1..16</a> %e A302145 Some solutions for n=5 %e A302145 ..0..1..1..1..1. .0..1..1..0..0. .0..1..1..0..0. .0..1..1..0..0 %e A302145 ..1..1..1..1..1. .1..1..0..0..0. .1..1..0..0..1. .1..1..0..0..1 %e A302145 ..1..1..1..1..0. .1..1..0..0..0. .1..1..0..0..0. .1..1..1..0..0 %e A302145 ..1..1..0..1..1. .1..1..1..0..0. .1..1..1..0..0. .1..1..0..0..0 %e A302145 ..1..1..1..1..0. .1..1..0..0..1. .1..1..0..0..1. .0..1..0..0..1 %Y A302145 Cf. A302150. %K A302145 nonn %O A302145 1,3 %A A302145 _R. H. Hardin_, Apr 02 2018