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A240701 Number of n X 3 0..3 arrays with no element equal to a different number of vertical neighbors than horizontal neighbors, with new values 0..3 introduced in row major order. 1
2, 27, 461, 7980, 138562, 2406061, 41780245, 725496762, 12597953186, 218758280685, 3798647658637, 65961955769536, 1145402258889550, 19889439592325187, 345371946166981361, 5997241935624779340 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 15*a(n-1) + 40*a(n-2) + 22*a(n-3) - 60*a(n-4) -  40*a(n-5) - 21*a(n-6) + 45*a(n-7).

Empirical g.f.: x*(2 - 3*x - 24*x^2 - 59*x^3 - 52*x^4 - 11*x^5 + 72*x^6) / ((1 - x)*(1 + x + x^2)*(1 - 15*x - 40*x^2 - 21*x^3 + 45*x^4)). - Colin Barker, Oct 29 2018

EXAMPLE

Some solutions for n=4:

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

..2..3..1....1..2..3....3..0..3....1..0..3....2..0..2....3..2..1....2..3..1

..0..1..3....0..0..1....1..2..0....2..2..0....0..1..3....2..0..3....0..1..2

..1..0..2....0..0..3....3..1..2....2..2..1....2..3..0....3..1..2....1..2..0

CROSSREFS

Column 3 of A240706.

Sequence in context: A278790 A277832 A221674 * A240638 A245050 A242009

Adjacent sequences:  A240698 A240699 A240700 * A240702 A240703 A240704

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 10 2014

STATUS

approved

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Last modified May 31 09:30 EDT 2020. Contains 334748 sequences. (Running on oeis4.)