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 A262915 #3 Oct 04 2015 10:12:31 %S A262915 1,43,261,2953,121507,1550557,33948145,1361585275,42115306149, %T A262915 1516528236361,61572663026659,2451674386383133,100125715548126961 %N A262915 Number of (n+1)X(6+1) 0..1 arrays with each row divisible by 3 and each column divisible by 7, read as a binary number with top and left being the most significant bits. %C A262915 Column 6 of A262917. %e A262915 Some solutions for n=4 %e A262915 ..0..0..0..0..0..0..0....1..0..0..1..1..1..0....0..1..0..0..0..0..1 %e A262915 ..0..1..0..0..0..0..1....1..1..0..1..0..0..1....0..1..0..0..0..0..1 %e A262915 ..0..1..0..0..1..1..1....1..1..0..1..1..1..1....0..1..0..0..1..1..1 %e A262915 ..0..1..0..0..1..1..1....0..1..0..0..0..0..1....0..0..0..0..1..1..0 %e A262915 ..0..0..0..0..1..1..0....0..0..0..0..1..1..0....0..0..0..0..1..1..0 %Y A262915 Cf. A262917. %K A262915 nonn %O A262915 1,2 %A A262915 _R. H. Hardin_, Oct 04 2015