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 A223985 #6 Jul 23 2025 04:45:56 %S A223985 610,52591,1738756,31585056,378122264,3322756326,22985966340, %T A223985 131366850521,642224541548,2756467192963,10596041132366, %U A223985 37055725164722,119377525079194,357900074208050,1006959166065982,2677364150668003 %N A223985 Number of nX6 0..3 arrays with rows unimodal and columns nondecreasing. %C A223985 Column 6 of A223987 %H A223985 R. H. Hardin, <a href="/A223985/b223985.txt">Table of n, a(n) for n = 1..210</a> %F A223985 Empirical: a(n) = (42587101/1600593426432000)*n^18 + (23341517/16167610368000)*n^17 + (1146376367/31384184832000)*n^16 + (6480623/11321856000)*n^15 + (97670169131/15692092416000)*n^14 + (12419845481/249080832000)*n^13 + (1104278423317/3621252096000)*n^12 + (292799530697/201180672000)*n^11 + (1205682607421/219469824000)*n^10 + (57526246621/3483648000)*n^9 + (95561855720567/2414168064000)*n^8 + (16411079047/217728000)*n^7 + (1328902382698939/11769069312000)*n^6 + (7779741596449/59439744000)*n^5 + (74800773679601/653837184000)*n^4 + (94051748107/1297296000)*n^3 + (483108777911/15437822400)*n^2 + (50380667/6126120)*n + 1 %e A223985 Some solutions for n=3 %e A223985 ..0..0..2..2..0..0....0..0..1..2..0..0....0..0..1..1..3..0....0..0..3..3..3..1 %e A223985 ..0..0..2..2..1..0....0..0..1..2..3..0....0..0..1..3..3..1....0..2..3..3..3..2 %e A223985 ..0..0..3..3..1..0....0..2..2..2..3..3....0..2..2..3..3..2....0..2..3..3..3..2 %K A223985 nonn %O A223985 1,1 %A A223985 _R. H. Hardin_ Mar 30 2013