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).

360, 2716, 20416, 153752, 1157728, 8726336, 65777344, 496308128, 3744934912, 28286490944, 213660702976, 1615562611712, 12215896488448, 92467959109376, 699922909794304, 5303754118235648, 40188257800148992, 304858331817979904

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

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

Adjacent sequences: A234547 A234548 A234549 * A234551 A234552 A234553

Keyword

nonn

Author

R. H. Hardin, Dec 28 2013

Status

approved