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A185475 Number of (n+2)X9 0..2 arrays with each 3X3 subblock having rows and columns in lexicographically nondecreasing order 1
336690, 3212372, 20411234, 100908633, 416227164, 1497314456, 4845252741, 14425457557, 40183952539, 106069534256, 267851235385, 651716593546, 1535886293189, 3519099305097, 7860273371841, 17147427400925, 36585315520514 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 7 of A185477

LINKS

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

FORMULA

Empirical: a(n) = (1/25519951134720000)*n^21

+ (1/127919554560000)*n^20

+ (1877/2551995113472000)*n^19

+ (101861/2328135892992000)*n^18

+ (10763959/5820339732480000)*n^17

+ (24725641/418455797760000)*n^16

+ (836589317/564915326976000)*n^15

+ (22655691343/753220435968000)*n^14

+ (5887296211331/11298306539520000)*n^13

+ (436620904451/52672757760000)*n^12

+ (3650470717199/28970016768000)*n^11

+ (2036750095277/1170505728000)*n^10

+ (1572848084986607/79009136640000)*n^9

+ (1160407108626427/6584094720000)*n^8

+ (2296534278781759/1975228416000)*n^7

+ (525799308273622787/94152554496000)*n^6

+ (25696337451699745273/1333827855360000)*n^5

+ (2682952836795541619/55576160640000)*n^4

+ (124299364108443341/1407929402880)*n^3

+ (73695052155737/701719200)*n^2

+ (1503827501467/23279256)*n

+ 4299

EXAMPLE

Some solutions for 4X9

..0..0..0..0..0..0..0..0..0....0..0..0..0..0..0..0..0..1

..0..0..0..0..0..0..0..1..2....0..0..0..0..0..0..0..0..1

..0..0..0..0..0..1..1..1..0....0..0..0..0..0..1..1..2..2

..0..0..0..1..2..1..2..2..0....0..0..0..0..1..1..2..1..2

CROSSREFS

Sequence in context: A234081 A022225 A114674 * A224632 A350186 A234726

Adjacent sequences:  A185472 A185473 A185474 * A185476 A185477 A185478

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 28 2011

STATUS

approved

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Last modified May 19 15:03 EDT 2022. Contains 353834 sequences. (Running on oeis4.)