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A218060 Number of n X 4 arrays of the minimum value of corresponding elements and their horizontal or antidiagonal neighbors in a random 0..1 n X 4 array. 1
6, 42, 260, 1664, 10566, 66978, 424332, 2687866, 17025060, 107835994, 683025864, 4326234664, 27402037744, 173562384900, 1099330676692, 6963075143418, 44103577188722, 279348632561274, 1769372542444278, 11207068261293544 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A218064.

LINKS

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

FORMULA

Empirical: a(n) = 9*a(n-1) - 18*a(n-2) + 6*a(n-3) + 7*a(n-4) - 2*a(n-5) - a(n-6) for n>7.

Empirical g.f.: 2*x*(3 - 6*x - 5*x^2 + 22*x^3 - 12*x^4 - 3*x^5 + 2*x^6) / ((1 - x)*(1 - 8*x + 10*x^2 + 4*x^3 - 3*x^4 - x^5)). - Colin Barker, Jul 23 2018

EXAMPLE

Some solutions for n=3:

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

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

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

CROSSREFS

Cf. A218064.

Sequence in context: A105281 A246938 A158797 * A283328 A343363 A331706

Adjacent sequences:  A218057 A218058 A218059 * A218061 A218062 A218063

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 19 2012

STATUS

approved

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Last modified November 28 12:00 EST 2021. Contains 349401 sequences. (Running on oeis4.)