A224171 Number of nX6 0..3 arrays with rows and antidiagonals unimodal and columns nondecreasing

610, 52591, 1253770, 15925611, 143558572, 1038484760, 6360047093, 33901838632, 160168789130, 680269560125, 2628521964178, 9335303943077, 30746296739238, 94635507313740, 274045375789233, 750986358734170, 1957473961121912

Offset

1,1

Comments

Column 6 of A224173

Links

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

Formula

Empirical: a(n) = (42587101/1600593426432000)*n^18 + (83940121/177843714048000)*n^17 + (308341547/31384184832000)*n^16 + (23656547/201180672000)*n^15 + (19255277651/15692092416000)*n^14 + (8091120109/747242496000)*n^13 + (255948441937/3621252096000)*n^12 + (100806994639/201180672000)*n^11 + (447955595981/219469824000)*n^10 + (936116756663/73156608000)*n^9 + (89792239149827/2414168064000)*n^8 + (167645449561/1026432000)*n^7 + (5108091310778959/11769069312000)*n^6 - (433115879452601/217945728000)*n^5 + (6324467156344901/653837184000)*n^4 - (35759831917609/698544000)*n^3 + (1815894225096923/15437822400)*n^2 + (1874103131609/6126120)*n - 1349188 for n>9

Example

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

Crossrefs

Sequence in context: A072317 A220568 A189455 * A223862 A223985 A224062

Adjacent sequences: A224168 A224169 A224170 * A224172 A224173 A224174

Keyword

nonn

Author

R. H. Hardin Mar 31 2013

Status

approved