A223860 Number of n X 4 0..3 arrays with rows and antidiagonals unimodal and columns nondecreasing.

130, 3526, 41682, 315124, 1771012, 8008548, 30627033, 102479569, 307435001, 842078930, 2135465204, 5069027730, 11361881611, 24219158218, 49385314943, 96803565005, 183160193142, 335692581558, 597766839750, 1036890170376

Offset

1,1

Comments

Column 4 of A223864.

Links

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

Formula

Empirical: a(n) = (3551/47900160)*n^12 + (3551/1995840)*n^11 + (100307/4354560)*n^10 + (28081/145152)*n^9 + (1559477/1451520)*n^8 + (14951/3456)*n^7 + (54414629/4354560)*n^6 + (18845069/725760)*n^5 + (41975947/1088640)*n^4 + (7155619/181440)*n^3 + (694249/83160)*n^2 - (7351/990)*n - 11 for n>1.

Example

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

Crossrefs

Cf. A223864.

Sequence in context: A228997 A168124 A224169 * A223983 A224060 A224046

Adjacent sequences: A223857 A223858 A223859 * A223861 A223862 A223863

Keyword

nonn

Author

R. H. Hardin, Mar 28 2013

Status

approved