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 A224189 #6 Jul 23 2025 05:02:01 %S A224189 239,9503,165212,1727738,12741432,72710554,340780382,1366188661, %T A224189 4823267213,15322738603,44529268480,119909493132,302279622352, %U A224189 719306742780,1626780581324,3516536949577,7300336446323,14614022023815 %N A224189 Number of nX7 0..2 arrays with rows unimodal and columns nondecreasing. %C A224189 Column 7 of A224190 %H A224189 R. H. Hardin, <a href="/A224189/b224189.txt">Table of n, a(n) for n = 1..210</a> %F A224189 Empirical: a(n) = (118519/21794572800)*n^14 + (93527/444787200)*n^13 + (6343/1710720)*n^12 + (9456619/239500800)*n^11 + (1028647/3628800)*n^10 + (10525213/7257600)*n^9 + (5190079/952560)*n^8 + (47462621/3110400)*n^7 + (99470417/3110400)*n^6 + (542507339/10886400)*n^5 + (226284461/3991680)*n^4 + (453542611/9979200)*n^3 + (60780847/2522520)*n^2 + (96119/12870)*n + 1 %e A224189 Some solutions for n=3 %e A224189 ..0..0..0..0..1..0..0....0..0..1..2..0..0..0....0..0..1..1..2..0..0 %e A224189 ..0..1..1..2..1..1..0....0..0..1..2..1..0..0....0..2..2..2..2..1..1 %e A224189 ..0..2..2..2..2..1..0....0..0..1..2..1..1..1....2..2..2..2..2..2..1 %K A224189 nonn %O A224189 1,1 %A A224189 _R. H. Hardin_ Apr 01 2013