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 A266463 #6 Apr 20 2020 19:43:35 %S A266463 2,4,12,66,735,18808,1231170,223521350,119000455681,193166954325425, %T A266463 983670413713595700 %N A266463 Number of n X n binary arrays with rows and columns lexicographically nondecreasing and column sums nonincreasing. %C A266463 Diagonal of A266470. %e A266463 Some solutions for n=4 %e A266463 ..0..0..0..0....0..0..1..1....0..0..0..1....0..0..0..0....0..1..1..1 %e A266463 ..0..0..1..1....1..1..0..1....0..1..1..0....0..0..0..1....1..0..0..1 %e A266463 ..1..1..0..0....1..1..1..0....1..0..0..0....0..0..1..0....1..0..1..0 %e A266463 ..1..1..1..1....1..1..1..0....1..1..1..1....1..1..0..0....1..1..0..0 %Y A266463 Cf. A266470. %K A266463 nonn %O A266463 1,1 %A A266463 _R. H. Hardin_, Dec 29 2015