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A234135
Number of (n+1) X (3+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
192, 296, 488, 968, 1992, 4808, 11336, 30536, 76872, 218696, 567368, 1657928, 4362312, 12916808, 34218056, 101986376, 271073352, 810573896, 2158002248, 6463471688, 17221877832, 51623592008, 137606856776, 412652601416
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*(24 - 35*x - 242*x^2 + 362*x^3 + 412*x^4 - 584*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 0 1 0 1 0 3 0 0 1 1 1 1 3 3 3 3
2 2 2 2 1 3 1 3 3 3 3 0 3 0 3 0 3 0 3 0
0 3 0 3 0 1 0 1 3 0 3 3 2 2 2 2 1 1 1 1
3 3 3 3 3 1 3 1 0 0 0 3 3 0 3 0 3 0 3 0
0 3 0 3 0 1 0 1 3 0 3 3 1 1 1 1 0 0 0 0
2 2 2 2 3 1 3 1 3 3 3 0 3 0 3 0 3 0 3 0
CROSSREFS
Column 3 of A234140.
Sequence in context: A273890 A344860 A045077 * A030632 A189987 A229361
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 19 2013
STATUS
approved