A223985 Number of nX6 0..3 arrays with rows unimodal and columns nondecreasing

610, 52591, 1738756, 31585056, 378122264, 3322756326, 22985966340, 131366850521, 642224541548, 2756467192963, 10596041132366, 37055725164722, 119377525079194, 357900074208050, 1006959166065982, 2677364150668003

Offset

1,1

Comments

Column 6 of A223987

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

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

Example

Some solutions for n=3
..0..0..2..2..0..0....0..0..1..2..0..0....0..0..1..1..3..0....0..0..3..3..3..1
..0..0..2..2..1..0....0..0..1..2..3..0....0..0..1..3..3..1....0..2..3..3..3..2
..0..0..3..3..1..0....0..2..2..2..3..3....0..2..2..3..3..2....0..2..3..3..3..2

Crossrefs

Sequence in context: A189455 A224171 A223862 * A224062 A224048 A224279

Adjacent sequences: A223982 A223983 A223984 * A223986 A223987 A223988

Keyword

nonn

Author

R. H. Hardin Mar 30 2013

Status

approved