A185475 Number of (n+2)X9 0..2 arrays with each 3X3 subblock having rows and columns in lexicographically nondecreasing order

336690, 3212372, 20411234, 100908633, 416227164, 1497314456, 4845252741, 14425457557, 40183952539, 106069534256, 267851235385, 651716593546, 1535886293189, 3519099305097, 7860273371841, 17147427400925, 36585315520514

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