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A234136
Number of (n+1) X (4+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
512, 680, 968, 1640, 2984, 6440, 14120, 35624, 86312, 236840, 602408, 1726760, 4497704, 13185320, 34750760, 103047464, 273187112, 814793000, 2166423848, 6480298280, 17255498024, 51690799400, 137741205800, 412921233704
OFFSET
1,1
LINKS
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*(64 - 107*x - 646*x^2 + 1082*x^3 + 1084*x^4 - 1736*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:
3 0 3 0 3 3 0 3 2 2 2 3 0 3 0 3 0 3 2 3
2 2 2 2 2 2 2 2 0 3 2 0 0 0 0 2 2 2 0 2
3 0 3 0 3 3 0 3 2 2 2 3 0 3 0 3 0 3 2 3
1 1 1 1 1 2 2 2 0 3 0 2 2 2 2 2 2 2 0 2
0 3 0 3 0 3 0 3 2 2 2 3 0 3 0 3 0 3 2 3
2 2 2 2 2 2 2 2 0 3 0 2 2 2 2 0 0 0 2 0
CROSSREFS
Column 4 of A234140.
Sequence in context: A217849 A326113 A045003 * A248536 A202461 A046311
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 19 2013
STATUS
approved