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A229444 Number of nX7 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, and rows and columns lexicographically nondecreasing 1
9, 32, 138, 665, 3184, 14536, 62205, 247607, 914271, 3133068, 9990129, 29755249, 83162347, 219151523, 547116607, 1299869098, 2951439969, 6429248828, 13483439736, 27310437901, 53577074678, 102061137870, 189220453845 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 7 of A229445

LINKS

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

FORMULA

Empirical: a(n) = (797/43589145600)*n^14 - (127/1245404160)*n^13 + (1/1451520)*n^12 + (335/19160064)*n^11 - (1381/10886400)*n^10 + (449/322560)*n^9 - (216523/30481920)*n^8 + (653459/8709120)*n^7 - (2384537/4838400)*n^6 + (2642473/870912)*n^5 - (275452937/23950080)*n^4 + (131909609/3991680)*n^3 - (38524939/687960)*n^2 + (21925483/360360)*n - 20

EXAMPLE

Some solutions for n=4

..0..0..0..0..2..2..2....0..0..0..2..2..2..2....0..0..2..2..2..2..2

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

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

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

CROSSREFS

Sequence in context: A225918 A231999 A297298 * A300773 A317279 A196016

Adjacent sequences:  A229441 A229442 A229443 * A229445 A229446 A229447

KEYWORD

nonn

AUTHOR

R. H. Hardin Sep 23 2013

STATUS

approved

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Last modified August 5 14:57 EDT 2021. Contains 346469 sequences. (Running on oeis4.)