A223826 Number of nX3 0..2 arrays with rows and columns unimodal

22, 484, 6166, 51136, 310396, 1492552, 5995781, 20879061, 64727664, 182215264, 472897132, 1144905802, 2610251996, 5646952970, 11664925145, 23128319257, 44207709722, 81762385076, 146787187114, 256501341004, 437310109972

Offset

1,1

Comments

Column 3 of A223831

Links

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

Formula

Empirical: a(n) = (5051/239500800)*n^12 + (17911/39916800)*n^11 + (113633/21772800)*n^10 + (27157/725760)*n^9 + (1331621/7257600)*n^8 + (36461/57600)*n^7 + (35192219/21772800)*n^6 + (2190431/725760)*n^5 + (24210049/5443200)*n^4 + (4187689/907200)*n^3 + (882989/207900)*n^2 + (2173/990)*n + 1

Example

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

Crossrefs

Sequence in context: A223635 A223720 A223667 * A223618 A223678 A223784

Adjacent sequences: A223823 A223824 A223825 * A223827 A223828 A223829

Keyword

nonn

Author

R. H. Hardin Mar 27 2013

Status

approved