A235191 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, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).

136, 512, 1880, 7072, 26040, 98080, 361688, 1364512, 5038200, 19038496, 70378904, 266376736, 985819704, 3737000224, 13845090392, 52561201696, 194934374904, 741091305760, 2751206637848, 10473426441760, 38917567088568

Offset

1,1

Links

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

Formula

Empirical: a(n) = 30*a(n-2) - 257*a(n-4) + 468*a(n-6).

Empirical g.f.: 8*x*(17 + 64*x - 275*x^2 - 1036*x^3 + 574*x^4 + 2188*x^5) / ((1 - 13*x^2)*(1 - 17*x^2 + 36*x^4)). - Colin Barker, Oct 17 2018

Example

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

Crossrefs

Column 1 of A235198.

Sequence in context: A116223 A124241 A235198 * A076331 A183901 A270341

Adjacent sequences: A235188 A235189 A235190 * A235192 A235193 A235194

Keyword

nonn

Author

R. H. Hardin, Jan 04 2014

Status

approved