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A189429 Number of n X 3 array permutations with each element not moving, or moving one space N, SW or SE. 1
1, 3, 9, 31, 109, 367, 1245, 4247, 14453, 49167, 167325, 569447, 1937829, 6594495, 22441517, 76369751, 259890293, 884421039, 3009733885, 10242290119, 34855077573, 118613751711, 403649138125, 1373640273207, 4674573594645 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 3 of A189435.

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) +4*a(n-2) +10*a(n-3) +12*a(n-4) +8*a(n-5).

Empirical g.f.: x*(1 + 2*x + 2*x^2) / (1 - x - 4*x^2 - 10*x^3 - 12*x^4 - 8*x^5). - Colin Barker, May 02 2018

EXAMPLE

Some solutions for 4 X 3:

..0..4..5....0..4..5....0..1..2....3..1..2....0..4..2....0..4..5....0..1..2

..6..2..1....1..2..8....3..7..5....6..0..5....1..7..5....3..2..1....3..4..5

..9..3..8....6..3.11....6.10..4....4.10.11....6..3..8....6..7..8....9.10..8

..7.10.11....9.10..7....9..8.11....9..8..7....9.10.11....9.10.11....7..6.11

CROSSREFS

Cf. A189435.

Sequence in context: A279971 A127927 A148967 * A123222 A148968 A148969

Adjacent sequences:  A189426 A189427 A189428 * A189430 A189431 A189432

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 22 2011

STATUS

approved

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Last modified August 12 16:40 EDT 2020. Contains 336439 sequences. (Running on oeis4.)