A224283 Number of 4Xn 0..3 arrays with diagonals and rows unimodal and antidiagonals nondecreasing

256, 16000, 186516, 1334973, 8073038, 44901359, 233090092, 1121852243, 4979825221, 20391024279, 77331512406, 273217833082, 905042600151, 2828381836611, 8387049692461, 23720147714267, 64273739402314

Offset

1,1

Comments

Row 4 of A224281

Links

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

Formula

Empirical: a(n) = (1/2906843957821440000)*n^24 + (1/80745665495040000)*n^23 + (46391/53523844179886080000)*n^22 + (11257/405483668029440000)*n^21 + (1330123/1390229718958080000)*n^20 + (8502743/347557429739520000)*n^19 + (35671/59779399680000)*n^18 + (133834769/10670622842880000)*n^17 + (7571063047/30128817438720000)*n^16 + (2965237343/836911595520000)*n^15 + (328422846067/15064408719360000)*n^14 + (22514281381/48910417920000)*n^13 + (7036550185081/2254537359360000)*n^12 - (105103493973601/2510734786560000)*n^11 + (1257210817095943/1076029194240000)*n^10 - (236735071681049/19615115520000)*n^9 + (3534310707922188979/32011868528640000)*n^8 - (767055210116438233/1143281018880000)*n^7 + (10350657608308971137/3103191336960000)*n^6 - (8154723578394294443/703964701440000)*n^5 + (16475873524529520931/527973526080000)*n^4 - (482012437494247/8888443200)*n^3 + (78892730856408401/873054262080)*n^2 - (77283877096589/243374040)*n + 643573 for n>7

Example

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

Crossrefs

Sequence in context: A017032 A136286 A269204 * A224206 A238064 A235964

Adjacent sequences: A224280 A224281 A224282 * A224284 A224285 A224286

Keyword

nonn

Author

R. H. Hardin Apr 02 2013

Status

approved