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 A269082 #7 Apr 19 2020 23:47:11 %S A269082 2,11,114,2238,80422,5372270,673690710,159449028034,71709929917104, %T A269082 61507638902069052,100988524469068110876,318195132133780181426070, %U A269082 1928131640777904103958251102,22507425106868892327680953474828 %N A269082 Number of n X n binary arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once. %C A269082 Diagonal of A269089. %H A269082 R. H. Hardin, <a href="/A269082/b269082.txt">Table of n, a(n) for n = 1..26</a> %e A269082 Some solutions for n=4 %e A269082 ..0..1..0..0. .1..1..0..1. .0..0..0..1. .0..1..0..0. .1..0..1..1 %e A269082 ..1..0..0..0. .0..0..0..0. .1..0..0..0. .0..0..0..1. .0..0..0..0 %e A269082 ..0..0..0..0. .0..0..0..1. .1..0..1..0. .0..0..0..0. .1..0..0..1 %e A269082 ..0..1..0..1. .1..0..0..0. .0..0..0..0. .1..0..0..0. .0..1..0..0 %Y A269082 Cf. A269089. %K A269082 nonn %O A269082 1,1 %A A269082 _R. H. Hardin_, Feb 19 2016