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A235205
Number of (n+1) X (1+1) 0..7 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 5, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).
1
240, 1172, 5696, 27812, 135520, 662892, 3236288, 15860868, 77573344, 380902284, 1866159680, 9179924964, 45049615456, 221990217900, 1091105210048, 5385447685188, 26509233788896, 131045666620620, 645952788233024
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) + 35*a(n-2) - 81*a(n-3) - 264*a(n-4) + 144*a(n-5) + 384*a(n-6).
Empirical g.f.: 4*x*(60 + 113*x - 1555*x^2 - 2714*x^3 + 2754*x^4 + 4784*x^5) / ((1 - 3*x - 8*x^2)*(1 - 27*x^2 + 48*x^4)). - Colin Barker, Oct 17 2018
EXAMPLE
Some solutions for n=5:
3 0 3 0 3 4 4 1 2 6 1 2 1 2 6 2 0 4 7 0
1 3 5 7 6 2 1 3 3 2 4 0 7 3 4 5 3 2 4 2
4 1 7 4 2 3 5 2 1 5 6 7 5 6 1 7 2 6 2 5
2 4 3 5 4 0 3 5 7 6 7 3 6 2 3 4 4 3 6 4
4 1 0 7 0 1 7 4 6 0 1 2 5 6 4 0 0 4 7 0
5 7 4 6 7 3 0 2 4 3 7 3 6 2 6 7 4 3 4 2
CROSSREFS
Column 1 of A235212.
Sequence in context: A234728 A234721 A235212 * A233878 A157766 A268906
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 04 2014
STATUS
approved