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 A201370 #8 Jul 22 2025 16:12:07 %S A201370 2,3,8,36,268,3739,115168,8866257,1799674094,976134459840 %N A201370 Number of n X n 0..1 arrays with rows and columns lexicographically nondecreasing read forwards, and nonincreasing read backwards. %C A201370 Diagonal of A201375 %e A201370 Some solutions for n=5 %e A201370 ..0..1..1..1..1....0..0..0..0..1....0..1..1..1..1....0..0..1..1..1 %e A201370 ..1..0..1..1..1....0..0..0..1..0....1..0..0..1..1....0..1..0..0..1 %e A201370 ..1..1..0..0..1....0..1..1..0..0....1..0..0..1..1....0..1..1..1..0 %e A201370 ..1..1..0..1..0....1..0..1..0..0....1..1..1..0..0....1..0..1..1..0 %e A201370 ..1..1..1..0..0....1..1..0..0..0....1..1..1..0..0....1..1..0..0..0 %K A201370 nonn %O A201370 1,1 %A A201370 _R. H. Hardin_ Nov 30 2011