A234326 Number of (n+1) X (1+1) 0..3 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 1 (constant-stress 1 X 1 tilings).

80, 432, 2368, 13056, 71936, 397056, 2188288, 12079104, 66572288, 367472640, 2025275392, 11179327488, 61613342720, 340099792896, 1874413748224, 10346585653248, 57023799492608, 314765950844928, 1734789723848704

Offset

1,1

Links

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

Formula

Empirical: a(n) = 32*a(n-2) - 48*a(n-4).

Empirical g.f.: 16*x*(5 + 27*x - 12*x^2 - 48*x^3) / (1 - 32*x^2 + 48*x^4). - Colin Barker, Oct 14 2018

Example

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

Crossrefs

Column 1 of A234333.

Sequence in context: A045657 A273292 A234333 * A085774 A233353 A233354

Adjacent sequences: A234323 A234324 A234325 * A234327 A234328 A234329

Keyword

nonn

Author

R. H. Hardin, Dec 23 2013

Status

approved