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A234185
Number of (n+1) X (1+1) 0..6 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 2 (constant-stress 1 X 1 tilings).
1
412, 3710, 33720, 307598, 2802904, 25588052, 233283984, 2130704612, 19434069328, 177586235768, 1620462346080, 14814614085176, 135240525352288, 1236977850187472, 11296995731446848, 103375851177954704
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 6*a(n-1) + 120*a(n-2) - 576*a(n-3) - 3026*a(n-4) + 5484*a(n-5) + 6720*a(n-6) - 10080*a(n-7).
Empirical g.f.: 2*x*(206 + 619*x - 18990*x^2 - 51305*x^3 + 147294*x^4 + 124320*x^5 - 246960*x^6) / ((1 - 6*x - 32*x^2 + 48*x^3)*(1 - 88*x^2 + 210*x^4)). - Colin Barker, Oct 13 2018
EXAMPLE
Some solutions for n=3:
6 4 6 5 0 1 5 2 5 3 3 6 4 5 0 5 5 5 3 5
4 0 4 5 3 2 4 3 6 6 1 2 1 4 1 4 6 4 2 2
2 0 4 3 5 2 5 6 2 0 2 5 2 3 1 2 3 3 6 4
6 2 5 6 6 1 2 5 3 3 0 5 1 4 6 5 0 2 6 6
CROSSREFS
Column 1 of A234190.
Sequence in context: A105211 A081378 A234190 * A282127 A344119 A257823
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 20 2013
STATUS
approved