A234683 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 5 (constant-stress 1 X 1 tilings).

232, 1148, 5472, 27344, 131200, 661952, 3196416, 16276736, 79071232, 406166528, 1984192512, 10274852864, 50451742720, 263191642112, 1298305253376, 6818128265216, 33772142067712, 178415166291968, 886967057252352

Offset

1,1

Links

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

Formula

Empirical: a(n) = 72*a(n-2) - 1712*a(n-4) + 13440*a(n-6).

Empirical g.f.: 4*x*(58 + 287*x - 2808*x^2 - 13828*x^3 + 33600*x^4 + 164640*x^5) / ((1 - 20*x^2)*(1 - 24*x^2)*(1 - 28*x^2)). - Colin Barker, Oct 16 2018

Example

Some solutions for n=5:
  0 6   1 3   4 1   4 0   6 0   1 5   1 5   0 0   5 3   0 2
  1 2   4 1   4 6   5 6   1 0   5 4   6 5   0 5   1 4   5 2
  0 6   3 5   6 3   4 0   0 4   6 0   6 0   0 0   2 0   3 5
  5 6   4 1   4 6   3 4   5 4   5 4   4 3   1 6   3 6   3 0
  0 6   0 2   6 3   6 2   2 6   1 5   1 5   5 5   2 0   3 5
  5 6   6 3   0 2   3 4   6 5   1 0   4 3   0 5   2 5   6 3

Crossrefs

Column 1 of A234690.

Sequence in context: A200870 A357573 A234690 * A366816 A238919 A327831

Adjacent sequences: A234680 A234681 A234682 * A234684 A234685 A234686

Keyword

nonn

Author

R. H. Hardin, Dec 29 2013

Status

approved