A224004 Number of 6Xn 0..2 arrays with antidiagonals unimodal and rows and diagonals nondecreasing

729, 20216, 117386, 388598, 984595, 2160036, 4368458, 8412641, 15703623, 28693082, 51589943, 91524689, 160402902, 277798382, 475383309, 803588211, 1341439640, 2210851797, 3597065144, 5777447600, 9161521721, 14345876103

Offset

1,1

Comments

Row 6 of A223999

Links

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

Formula

Empirical: a(n) = (1/3628800)*n^12 + (1/302400)*n^11 + (419/3628800)*n^10 + (223/120960)*n^9 + (35411/1209600)*n^8 + (20443/50400)*n^7 + (17616857/3628800)*n^6 + (6342323/120960)*n^5 + (821276033/1814400)*n^4 + (103253527/37800)*n^3 + (186412339/16800)*n^2 - (24901729/840)*n - 64275 for n>8

Example

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

Crossrefs

Sequence in context: A209508 A016758 A183809 * A232028 A203651 A036536

Adjacent sequences: A224001 A224002 A224003 * A224005 A224006 A224007

Keyword

nonn

Author

R. H. Hardin Mar 30 2013

Status

approved