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

Author

R. H. Hardin Apr 02 2013

Keywords

• nonn

Comments

Row 4 of A224281

Examples

			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
		

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