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 A200709 #7 May 04 2023 12:19:57 %S A200709 154,7370,317656,12904303,501622631,18836416881,688892422045, %T A200709 24679562321720,870010030574894,30274045926194001,1042315568516067529, %U A200709 35569907932628823872,1204745819326637993000,40540325062931324645529 %N A200709 Number of n X 3 0..7 arrays with every row and column running average nondecreasing rightwards and downwards. %C A200709 Column 3 of A200713. %H A200709 R. H. Hardin, <a href="/A200709/b200709.txt">Table of n, a(n) for n = 1..23</a> %e A200709 Some solutions for n=4 %e A200709 ..0..4..7....0..0..3....0..0..1....0..0..1....0..0..0....0..2..2....0..2..2 %e A200709 ..0..4..7....0..0..5....0..4..3....0..0..4....0..2..1....0..2..7....0..4..7 %e A200709 ..0..6..7....0..4..6....0..2..3....0..0..5....0..4..3....0..4..6....0..4..7 %e A200709 ..1..6..7....0..3..7....0..5..3....2..2..7....0..5..4....0..4..5....0..6..6 %Y A200709 Cf. A200713. %K A200709 nonn %O A200709 1,1 %A A200709 _R. H. Hardin_, Nov 20 2011