A201697 Number of nX5 0..2 arrays with rows and columns lexicographically nondecreasing read forwards and nonincreasing read backwards

3, 37, 989, 35390, 930564, 14268351, 142436489, 1034563890, 5898023820, 27803725006, 112491133042, 401503571755, 1290797861479, 3798580774670, 10363168825912, 26478119492263, 63883865534377, 146539437113683

Offset

1,1

Comments

Column 5 of A201700

Links

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

Formula

Empirical: a(n) = (39619/523069747200)*n^16 + (4468181/653837184000)*n^15 + (29013757/130767436800)*n^14 + (1283689/849139200)*n^13 - (51508993/2874009600)*n^12 - (43603801/256608000)*n^11 + (2874162577/914457600)*n^10 - (7499289487/457228800)*n^9 + (16169769137/731566080)*n^8 + (30409918103/653184000)*n^7 + (408990763441/718502400)*n^6 - (175356370649/25660800)*n^5 + (317152595889599/10897286400)*n^4 - (27799492117129/412776000)*n^3 + (2720484273811/30270240)*n^2 - (23317530409/360360)*n + 19289

Example

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

Crossrefs

Sequence in context: A331656 A003717 A354020 * A274308 A318224 A300986

Adjacent sequences: A201694 A201695 A201696 * A201698 A201699 A201700

Keyword

nonn

Author

R. H. Hardin Dec 03 2011

Status

approved