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 A200983 #8 Jul 22 2025 16:02:39 %S A200983 5,10,92,1225,4919,752271,29555346,1278883650,65182166083,731587297275 %N A200983 Number of n X n 0..4 arrays with every row and column nondecreasing rightwards and downwards, and the number of instances of each value within one of each other. %C A200983 Diagonal of A200990 %e A200983 Some solutions for n=3 %e A200983 ..0..0..1....0..2..3....0..1..2....0..0..2....0..1..1....0..1..3....0..2..2 %e A200983 ..1..3..4....1..2..4....0..2..3....1..2..3....2..3..4....0..1..4....1..3..3 %e A200983 ..2..3..4....1..3..4....1..4..4....1..3..4....2..3..4....2..2..4....1..4..4 %K A200983 nonn %O A200983 1,1 %A A200983 _R. H. Hardin_ Nov 25 2011