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A218517 Number of n X 3 arrays of the minimum value of corresponding elements and their horizontal or antidiagonal neighbors in a random 0..3 n X 3 array. 1
16, 286, 4634, 76214, 1254462, 20655650, 340133516, 5601018048, 92232936766, 1518816980614, 25010647012824, 411855079591306, 6782095959978908, 111682064830460636, 1839089815861812230, 30284641999299892776 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A218522.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..157

FORMULA

Empirical: a(n) = 18*a(n-1) - 19*a(n-2) - 96*a(n-3) - 112*a(n-4) - a(n-5) + 140*a(n-6) + 64*a(n-7).

Empirical g.f.: 2*x*(8 - x - 105*x^2 - 114*x^3 - 48*x^4 + 156*x^5 + 96*x^6) / (1 - 18*x + 19*x^2 + 96*x^3 + 112*x^4 + x^5 - 140*x^6 - 64*x^7). - Colin Barker, Jul 24 2018

EXAMPLE

Some solutions for n=3:

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

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

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

CROSSREFS

Cf. A218522.

Sequence in context: A299356 A299177 A299939 * A230347 A182608 A320763

Adjacent sequences:  A218514 A218515 A218516 * A218518 A218519 A218520

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 31 2012

STATUS

approved

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Last modified September 16 21:28 EDT 2021. Contains 347473 sequences. (Running on oeis4.)