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A218898 Number of 2 X n arrays of the minimum value of corresponding elements and their horizontal, diagonal or antidiagonal neighbors in a random 0..1 2 X n array. 1
4, 6, 18, 34, 86, 180, 426, 930, 2140, 4758, 10818, 24240, 54834, 123274, 278260, 626446, 1412746, 3182416, 7174106, 16164834, 36434260, 82103270, 185041218, 417002816, 939796802, 2117936730, 4773120596, 10756848350, 24242204506 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 2 of A218897.

LINKS

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

FORMULA

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

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

EXAMPLE

Some solutions for n=3:

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

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

CROSSREFS

Cf. A218897.

Sequence in context: A182643 A156096 A281861 * A088810 A005199 A107390

Adjacent sequences:  A218895 A218896 A218897 * A218899 A218900 A218901

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 08 2012

STATUS

approved

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Last modified February 16 05:10 EST 2019. Contains 320140 sequences. (Running on oeis4.)