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 A240655 #6 Apr 25 2023 13:13:59 %S A240655 1,21,402,7154,118863,2076117,37066859,666849212,12062165754, %T A240655 218944306666,3980414427158,72424065007263,1318344476372801, %U A240655 24003514023779867,437093903871650760,7959828410582705257 %N A240655 Number of n X 7 0..1 arrays with no element equal to exactly one horizontal or vertical neighbor, with new values 0..1 introduced in row major order. %C A240655 Column 7 of A240656. %H A240655 R. H. Hardin, <a href="/A240655/b240655.txt">Table of n, a(n) for n = 1..210</a> %e A240655 Some solutions for n=4 %e A240655 ..0..0..0..0..0..0..1....0..1..1..1..1..1..1....0..0..0..1..0..0..0 %e A240655 ..0..0..1..0..0..0..0....1..1..0..1..0..0..1....0..0..0..0..0..0..0 %e A240655 ..0..0..0..1..0..0..0....1..1..1..1..0..0..1....0..1..0..1..0..0..0 %e A240655 ..0..0..0..0..0..0..0....0..1..1..1..1..1..1....0..0..0..0..0..0..1 %Y A240655 Cf. A240656. %K A240655 nonn %O A240655 1,2 %A A240655 _R. H. Hardin_, Apr 09 2014