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 A266422 #6 Apr 20 2020 19:43:11 %S A266422 2,7,39,404,8764,448649,59155748,21325003746,21901867532457, %T A266422 66087854484252677,600640567173169508177 %N A266422 Number of n X n binary arrays with rows and columns lexicographically nondecreasing and column sums nondecreasing. %C A266422 Diagonal of A266428. %e A266422 Some solutions for n=4 %e A266422 ..0..0..0..1....0..0..0..0....0..0..1..1....0..0..0..0....0..0..1..1 %e A266422 ..0..1..1..1....0..1..1..1....0..1..0..0....0..0..1..1....0..1..0..1 %e A266422 ..1..0..1..1....1..0..0..1....1..0..1..1....0..1..0..0....0..1..1..1 %e A266422 ..1..1..1..1....1..1..1..0....1..1..0..1....1..0..1..1....1..0..0..1 %Y A266422 Cf. A266428. %K A266422 nonn %O A266422 1,1 %A A266422 _R. H. Hardin_, Dec 29 2015