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 A223862 #6 Jul 23 2025 04:36:02 %S A223862 610,52591,1477240,22852913,243933798,1989679315,13140481520, %T A223862 73068868012,352040804450,1502130487437,5774921786002,20281095690376, %U A223862 65798275499953,199037907806762,565735226772194,1520829902726663,3888227083552907 %N A223862 Number of nX6 0..3 arrays with rows and antidiagonals unimodal and columns nondecreasing. %C A223862 Column 6 of A223864 %H A223862 R. H. Hardin, <a href="/A223862/b223862.txt">Table of n, a(n) for n = 1..210</a> %F A223862 Empirical: a(n) = (42587101/1600593426432000)*n^18 + (42587101/44460928512000)*n^17 + (315292339/15692092416000)*n^16 + (41939983/145297152000)*n^15 + (4407829651/1426553856000)*n^14 + (41324477/1596672000)*n^13 + (19314677849/113164128000)*n^12 + (2898049019/3143448000)*n^11 + (876424981241/219469824000)*n^10 + (28801840747/2032128000)*n^9 + (50450804070829/1207084032000)*n^8 + (17909311831/177408000)*n^7 + (265168304450783/1471133664000)*n^6 + (27553165793177/163459296000)*n^5 - (2984221796923/29719872000)*n^4 - (816413565637/1009008000)*n^3 - (1198736836439/7718911200)*n^2 + (2348655877/471240)*n - 5035 for n>4 %e A223862 Some solutions for n=3 %e A223862 ..0..0..1..2..0..0....0..0..1..2..3..2....0..0..2..1..0..0....0..2..2..2..2..0 %e A223862 ..0..2..2..2..2..0....0..0..2..3..3..2....0..0..2..2..2..0....0..2..3..3..2..1 %e A223862 ..0..2..3..3..3..2....0..0..2..3..3..2....0..0..3..3..3..3....0..2..3..3..3..2 %K A223862 nonn %O A223862 1,1 %A A223862 _R. H. Hardin_ Mar 28 2013