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 A223861 #6 Jul 23 2025 04:35:55 %S A223861 296,14751,273959,3017129,23738426,145947740,740441932,3217594840, %T A223861 12305144319,42270004211,132509660564,383868226325,1038081470947, %U A223861 2642374422155,6374651949942,14659617536977,32293516183091 %N A223861 Number of nX5 0..3 arrays with rows and antidiagonals unimodal and columns nondecreasing. %C A223861 Column 5 of A223864 %H A223861 R. H. Hardin, <a href="/A223861/b223861.txt">Table of n, a(n) for n = 1..210</a> %F A223861 Empirical: a(n) = (769/444787200)*n^15 + (769/14826240)*n^14 + (1364177/1556755200)*n^13 + (4745443/479001600)*n^12 + (19610293/239500800)*n^11 + (21660577/43545600)*n^10 + (51383569/21772800)*n^9 + (4604039/537600)*n^8 + (65760287/2721600)*n^7 + (2366026111/43545600)*n^6 + (21481491623/239500800)*n^5 + (11196959227/119750400)*n^4 - (1120821577/51891840)*n^3 - (1312521589/10810800)*n^2 + (8123611/51480)*n - 113 for n>2 %e A223861 Some solutions for n=3 %e A223861 ..0..0..0..0..1....0..0..1..1..0....0..0..0..0..0....0..0..1..0..0 %e A223861 ..0..0..1..1..1....0..0..1..1..0....2..2..1..0..0....0..0..1..3..1 %e A223861 ..3..3..2..2..1....0..0..1..3..0....3..3..1..0..0....0..1..2..3..1 %K A223861 nonn %O A223861 1,1 %A A223861 _R. H. Hardin_ Mar 28 2013