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A234139 Number of (n+1) X (7+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
9216, 9992, 11336, 14120, 19368, 30632, 53288, 104744, 214056, 481832, 1079336, 2667560, 6361128, 16893992, 42139688, 117796904, 302637096, 873644072, 2284036136, 6715433000, 17725595688, 52630822952, 139620917288, 416680321064 (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*(1152 - 2207*x - 11546*x^2 + 22082*x^3 + 18652*x^4 - 35336*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 3 1 3 3 0      0 3 3 3 3 0 3 0      2 0 1 3 1 3 1 3

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

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

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

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

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

CROSSREFS

Column 7 of A234140.

Sequence in context: A231424 A234887 A251902 * A175743 A204103 A209595

Adjacent sequences:  A234136 A234137 A234138 * A234140 A234141 A234142

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 19 2013

STATUS

approved

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Last modified June 25 12:30 EDT 2022. Contains 354851 sequences. (Running on oeis4.)