A224188 Number of n X 6 0..2 arrays with rows unimodal and columns nondecreasing.

148, 4102, 52591, 422488, 2469182, 11444292, 44435746, 150015321, 452158538, 1240740774, 3145970477, 7456438392, 16672410340, 35430409240, 71995370532, 140596619273, 264988109400, 483746928198, 857992826459, 1482422036736

Offset

1,1

Comments

Column 6 of A224190.

Links

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

Formula

Empirical: a(n) = (761/8553600)*n^12 + (811/302400)*n^11 + (98797/2721600)*n^10 + (105751/362880)*n^9 + (2800757/1814400)*n^8 + (429167/75600)*n^7 + (1442737/97200)*n^6 + (373033/13440)*n^5 + (100027061/2721600)*n^4 + (15191569/453600)*n^3 + (16485617/831600)*n^2 + (4273/630)*n + 1.

Example

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

Crossrefs

Sequence in context: A338970 A224260 A223916 * A223931 A224055 A224308

Adjacent sequences: A224185 A224186 A224187 * A224189 A224190 A224191

Keyword

nonn

Author

R. H. Hardin, Apr 01 2013

Status

approved