A185469 Number of (n+2)X3 0..2 arrays with each 3X3 subblock having rows and columns in lexicographically nondecreasing order

1169, 4594, 13659, 34779, 79743, 169052, 336690, 636698, 1151966, 2005704, 3376100, 5514721, 8769262, 13611298, 20669745, 30770788, 44985087, 64683126, 91599625, 127907991, 176305841, 240112688, 323380940, 431021422, 568944692

Offset

1,1

Comments

Column 1 of A185477

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = (1/362880)*n^9

+ (1/1008)*n^8

+ (431/12096)*n^7

+ (373/720)*n^6

+ (82453/17280)*n^5

+ (637/18)*n^4

+ (2819461/18144)*n^3

+ (119729/315)*n^2

+ (605807/1260)*n

+ 112

Example

Some solutions for 4X3
..1..1..2....0..1..2....0..0..0....0..1..2....0..0..1....0..0..0....0..0..2
..1..1..2....0..1..2....0..0..2....0..1..2....0..1..1....0..0..2....0..2..2
..1..2..1....0..1..2....0..2..1....1..1..0....0..2..2....0..1..0....1..0..1
..2..0..1....2..1..2....2..0..0....2..0..1....1..0..1....0..2..0....2..0..2

Crossrefs

Sequence in context: A252009 A032744 A185477 * A065656 A185468 A209825

Adjacent sequences: A185466 A185467 A185468 * A185470 A185471 A185472

Keyword

nonn

Author

R. H. Hardin Jan 28 2011

Status

approved