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A185469 Number of (n+2)X3 0..2 arrays with each 3X3 subblock having rows and columns in lexicographically nondecreasing order 1
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified December 5 12:24 EST 2021. Contains 349557 sequences. (Running on oeis4.)