A224058 Number of nX2 0..3 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing

16, 160, 984, 4580, 17723, 59792, 180821, 499357, 1276595, 3053471, 6892199, 14784563, 30317821, 59727346, 113515445, 208880837, 373286086, 649594326, 1103335758, 1832822970, 2983026931, 4764357840, 7477772697, 11547960881

Offset

1,1

Comments

Column 2 of A224064

Links

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

Formula

Empirical: a(n) = (1/19160064)*n^12 + (1/456192)*n^11 + (2287/43545600)*n^10 + (215/290304)*n^9 + (2861/414720)*n^8 + (7187/161280)*n^7 + (10695901/43545600)*n^6 + (212027/207360)*n^5 + (6072841/2177280)*n^4 + (1652783/362880)*n^3 + (1059277/237600)*n^2 + (26023/13860)*n + 1

Example

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

Crossrefs

Sequence in context: A180798 A144453 A121036 * A073394 A038846 A079767

Adjacent sequences: A224055 A224056 A224057 * A224059 A224060 A224061

Keyword

nonn

Author

R. H. Hardin Mar 30 2013

Status

approved