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 A200988 #7 Jul 22 2025 16:03:05 %S A200988 5,226,3157,15023,27000,752271,8434277,39361323,80878071,64001290, %T A200988 1061617971,6885026630,20690808333,29111264965,15934951732, %U A200988 200246707818,986856290325,2324162438865,2632647531203,1170193845706,12359035000524 %N A200988 Number of nX6 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 A200988 Column 6 of A200990 %H A200988 R. H. Hardin, <a href="/A200988/b200988.txt">Table of n, a(n) for n = 1..22</a> %e A200988 Some solutions for n=3 %e A200988 ..0..0..0..1..1..4....0..0..1..1..2..3....0..0..1..1..2..2....0..0..0..2..2..4 %e A200988 ..0..1..2..3..3..4....0..1..1..3..3..4....0..1..2..3..3..4....0..1..2..3..3..4 %e A200988 ..1..2..2..3..4..4....2..2..2..4..4..4....1..3..3..4..4..4....1..1..3..3..4..4 %K A200988 nonn %O A200988 1,1 %A A200988 _R. H. Hardin_ Nov 25 2011