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A218892 Number of n X 3 arrays of the minimum value of corresponding elements and their horizontal, diagonal or antidiagonal neighbors in a random 0..1 n X 3 array. 1
4, 18, 72, 286, 1162, 4700, 19046, 77198, 312944, 1268694, 5143506, 20852924, 84542894, 342758566, 1389632608, 5633935678, 22841460250, 92605309212, 375446383830, 1522158836638, 6171234143440, 25019814013190, 101436937848962 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A218897.

LINKS

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

FORMULA

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

Empirical g.f.: 2*x*(2 + x - 4*x^2 - 9*x^3 - 2*x^4) / (1 - 4*x - 2*x^2 + 5*x^3 + 8*x^4 + 4*x^5). - Colin Barker, Jul 24 2018

EXAMPLE

Some solutions for n=3:

..0..0..1....1..0..1....0..0..0....0..0..0....0..0..1....0..0..0....0..0..1

..1..0..1....0..0..0....0..0..0....1..0..0....0..0..1....0..0..0....1..0..0

..0..0..0....1..0..0....0..0..0....1..0..1....1..0..1....1..0..1....1..0..0

CROSSREFS

Cf. A218897.

Sequence in context: A159715 A027261 A290919 * A307566 A117615 A267450

Adjacent sequences:  A218889 A218890 A218891 * A218893 A218894 A218895

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 08 2012

STATUS

approved

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Last modified September 24 10:18 EDT 2020. Contains 337317 sequences. (Running on oeis4.)