A224357 Number of 6Xn 0..2 arrays with diagonals and antidiagonals unimodal and rows nondecreasing

729, 46656, 349280, 1351748, 4231138, 12340932, 34697869, 94262290, 246254814, 616242552, 1475123504, 3379586703, 7423803582, 15672970622, 31884279651, 62668814332, 119312143790, 220555944774, 396752366132, 695942226325

Offset

1,1

Comments

Row 6 of A224353

Links

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

Formula

Empirical: a(n) = (761/8553600)*n^12 + (1733/3326400)*n^11 + (1459/108864)*n^10 + (4187/40320)*n^9 + (1551227/1814400)*n^8 + (72841/12600)*n^7 + (1802801/19440)*n^6 - (66259339/120960)*n^5 + (9020552353/1360800)*n^4 - (817656577/50400)*n^3 + (5508355001/83160)*n^2 - (57456263/1540)*n - 269256 for n>7

Example

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

Crossrefs

Sequence in context: A036536 A223281 A268976 * A016770 A224016 A059978

Adjacent sequences: A224354 A224355 A224356 * A224358 A224359 A224360

Keyword

nonn

Author

R. H. Hardin Apr 04 2013

Status

approved