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 A301607 #4 Mar 24 2018 11:33:10 %S A301607 1,21,55,755,6393,60841,591585,5880829,58383932,585233819,5854941545, %T A301607 58759934077,589360075403,5914609427757,59355963113549, %U A301607 595731234612875,5979121155775603,60011713256358774,602331412174313879 %N A301607 Number of nX7 0..1 arrays with every element equal to 0, 2 or 3 horizontally or vertically adjacent elements, with upper left element zero. %C A301607 Column 7 of A301608. %H A301607 R. H. Hardin, <a href="/A301607/b301607.txt">Table of n, a(n) for n = 1..210</a> %e A301607 Some solutions for n=5 %e A301607 ..0..0..1..1..0..0..0. .0..0..0..0..0..0..1. .0..0..0..0..0..1..1 %e A301607 ..0..0..1..1..0..1..0. .0..0..1..1..0..0..0. .0..0..1..0..0..1..1 %e A301607 ..0..0..1..1..0..0..0. .1..0..1..1..0..1..0. .1..1..0..0..0..1..1 %e A301607 ..1..1..0..1..1..1..1. .0..0..1..1..0..0..0. .1..1..0..1..0..0..0 %e A301607 ..1..1..1..1..0..1..1. .0..0..1..1..0..0..1. .1..1..0..0..0..0..0 %Y A301607 Cf. A301608. %K A301607 nonn %O A301607 1,2 %A A301607 _R. H. Hardin_, Mar 24 2018