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A234550
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 3 (constant-stress 1 X 1 tilings).
1
360, 2716, 20416, 153752, 1157728, 8726336, 65777344, 496308128, 3744934912, 28286490944, 213660702976, 1615562611712, 12215896488448, 92467959109376, 699922909794304, 5303754118235648, 40188257800148992, 304858331817979904
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 118*a(n-2) - 3660*a(n-4) + 10800*a(n-6).
Empirical g.f.: 4*x*(90 + 679*x - 5516*x^2 - 41684*x^3 + 16560*x^4 + 131040*x^5) / ((1 - 60*x^2)*(1 - 58*x^2 + 180*x^4)). - Colin Barker, Oct 15 2018
EXAMPLE
Some solutions for n=4:
2 4 0 5 1 3 4 6 3 4 1 2 2 2 0 3 4 2 0 1
1 0 2 4 5 4 2 1 2 0 1 5 3 0 0 0 4 5 3 1
2 4 3 2 0 2 1 3 3 4 0 1 5 5 1 4 2 0 2 3
5 4 0 2 3 2 1 0 2 0 3 1 6 3 5 5 2 3 4 2
4 0 2 1 4 0 4 0 5 6 4 5 6 6 3 6 1 5 6 1
CROSSREFS
Column 1 of A234555.
Sequence in context: A056390 A056380 A234555 * A024185 A033592 A305626
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 28 2013
STATUS
approved