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A234138 Number of (n+1) X (6+1) 0..3 arrays with every 2 X 2 subblock having the sum of the absolute values of all six edge and diagonal differences equal to 9. 1
3584, 4040, 4808, 6440, 9512, 16424, 30632, 65192, 141224, 342440, 807848, 2131880, 5299112, 14779304, 37923752, 109378472, 285821864, 840035240, 2216856488, 6581111720, 17457023912, 52093750184, 138546908072, 414532438952 (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) = 3*a(n-1) + 8*a(n-2) - 30*a(n-3) + 4*a(n-4) + 48*a(n-5) - 32*a(n-6).

Empirical g.f.: 8*x*(448 - 839*x - 4498*x^2 + 8402*x^3 + 7324*x^4 - 13448*x^5) / ((1 - x)*(1 - 2*x)*(1 - 2*x^2)*(1 - 8*x^2)). - Colin Barker, Oct 13 2018

EXAMPLE

Some solutions for n=5:

  0 3 3 0 3 0 3       0 0 1 3 3 0 3       3 3 0 0 3 3 3

  0 0 3 3 3 3 3       0 3 1 0 3 3 3       0 3 3 0 0 3 0

  3 0 0 3 0 3 0       0 0 1 3 3 0 3       3 3 0 0 3 3 3

  0 0 3 3 3 3 3       0 3 1 0 3 3 3       3 0 0 3 3 0 3

  3 0 0 3 0 3 0       0 0 1 3 3 0 3       3 3 0 0 3 3 3

  3 3 0 0 0 0 0       0 3 1 0 3 3 3       0 3 3 0 0 3 0

CROSSREFS

Column 6 of A234140.

Sequence in context: A004972 A246855 A252153 * A249289 A249537 A156845

Adjacent sequences:  A234135 A234136 A234137 * A234139 A234140 A234141

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 19 2013

STATUS

approved

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Last modified November 17 18:24 EST 2019. Contains 329241 sequences. (Running on oeis4.)