A224016 Number of 6Xn 0..2 arrays with rows nondecreasing and antidiagonals unimodal

729, 46656, 534352, 3094127, 13275381, 47735665, 150787422, 430109607, 1128769430, 2762176256, 6366017979, 13926332849, 29098170483, 58367669325, 112877225362, 211218704199, 383609908528, 678009948228, 1168905645807

Offset

1,1

Comments

Row 6 of A224012

Links

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

Formula

Empirical: a(n) = (761/8553600)*n^12 + (811/302400)*n^11 + (4879/97200)*n^10 + (230029/362880)*n^9 + (10666727/1814400)*n^8 + (6162019/151200)*n^7 + (76144063/388800)*n^6 + (1772311/2688)*n^5 + (230134279/194400)*n^4 + (14927389/453600)*n^3 - (7982908/51975)*n^2 + (2910398/315)*n + 7207 for n>4

Example

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

Crossrefs

Sequence in context: A268976 A224357 A016770 * A059978 A223208 A005608

Adjacent sequences: A224013 A224014 A224015 * A224017 A224018 A224019

Keyword

nonn

Author

R. H. Hardin Mar 30 2013

Status

approved