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 A214005 #8 Nov 10 2014 17:35:12 %S A214005 2,12,271,24950,9800058,16942485560,131898088386405, %T A214005 4704783844260626244 %N A214005 Number of n X n nonnegative integer matrices with row and column i=1..n having sum <= i. %C A214005 Column 1 of A214011. %e A214005 Some solutions for n=3: %e A214005 ..1..0..0....0..1..0....0..0..0....0..1..0....0..0..0....0..1..0....0..0..1 %e A214005 ..0..1..1....0..1..0....0..0..1....1..0..0....0..1..1....0..0..1....1..0..0 %e A214005 ..0..0..2....0..0..1....0..0..2....0..1..0....0..0..1....0..0..0....0..0..1 %Y A214005 Cf. A214011. %K A214005 nonn,more %O A214005 1,1 %A A214005 _R. H. Hardin_, Jun 30 2012