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A234222
Number of (n+1) X (3+1) 0..4 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
1824, 5612, 17448, 56936, 188040, 648536, 2264904, 8215256, 30142344, 114224792, 436849608, 1716521816, 6787144200, 27449810456, 111385692744, 460731399896, 1906999712904, 8026422662552, 33728591085768, 143889611473496
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 9*a(n-1) +20*a(n-2) -390*a(n-3) +460*a(n-4) +5520*a(n-5) -14240*a(n-6) -26400*a(n-7) +115776*a(n-8) -13824*a(n-9) -299520*a(n-10) +276480*a(n-11).
EXAMPLE
Some solutions for n=5:
1 1 1 3 1 3 0 0 2 1 2 4 0 2 4 4 1 4 1 1
1 4 1 0 2 1 1 4 4 0 4 3 2 1 0 3 3 3 3 0
0 0 0 2 4 0 3 3 4 3 4 0 2 4 0 0 4 1 4 4
1 4 1 0 1 0 0 3 4 0 4 3 3 2 1 4 1 1 1 4
2 2 2 4 4 0 3 3 1 0 1 3 4 0 2 2 4 1 4 4
4 1 4 3 2 1 1 4 4 0 4 3 3 2 1 4 0 0 0 3
CROSSREFS
Column 3 of A234227.
Sequence in context: A256076 A179581 A230052 * A233813 A249536 A124073
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 21 2013
STATUS
approved