A234883 Number of (n+1) X (1+1) 0..5 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 1, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).

80, 272, 856, 2896, 9192, 31064, 98696, 333456, 1059616, 3579832, 11375904, 38432120, 122129480, 412598472, 1311156208, 4429566640, 14076290136, 47554864016, 151120001288, 510538698456, 1622391563368, 5481032709232

Offset

1,1

Links

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

Formula

Empirical: a(n) = 14*a(n-2) - 37*a(n-4) + 21*a(n-6).

Empirical g.f.: 8*x*(10 + 34*x - 33*x^2 - 114*x^3 + 21*x^4 + 73*x^5) / (1 - 14*x^2 + 37*x^4 - 21*x^6). - Colin Barker, Oct 16 2018

Example

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

Crossrefs

Column 1 of A234890.

Sequence in context: A306434 A234890 A157912 * A194646 A057441 A204483

Adjacent sequences: A234880 A234881 A234882 * A234884 A234885 A234886

Keyword

nonn

Author

R. H. Hardin, Jan 01 2014

Status

approved