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 A202712 #7 Jul 22 2025 16:46:47 %S A202712 3,10,624,173860,421158558,8496020082856 %N A202712 Number of n X n 0..2 arrays with row sums equal and no column sum equal to the previous. %C A202712 Column 2 of A202714 %e A202712 Some solutions for n=3 %e A202712 ..0..2..1....1..1..1....0..0..2....0..2..2....0..1..1....2..0..0....1..0..2 %e A202712 ..0..2..1....1..2..0....2..0..0....0..2..2....2..0..0....0..2..0....2..1..0 %e A202712 ..1..1..1....2..0..1....2..0..0....1..1..2....0..0..2....2..0..0....0..1..2 %K A202712 nonn %O A202712 1,1 %A A202712 _R. H. Hardin_ Dec 23 2011