A234905 Number of (n+1) X (1+1) 0..7 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).

280, 1720, 10344, 65048, 395992, 2497560, 15235088, 96142104, 586688280, 3702734168, 22596846536, 142617229960, 870368867864, 5493248738432, 33524459064760, 211586539448504, 1291281038431688, 8149802725166840

Offset

1,1

Links

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

Formula

Empirical: a(n) = 55*a(n-2) -725*a(n-4) +3663*a(n-6) -7525*a(n-8) +6335*a(n-10) -1805*a(n-12).

Example

Some solutions for n=4:
  0 2   5 4   5 7   1 0   7 5   5 2   4 0   4 7   1 3   3 1
  4 7   7 5   0 3   6 4   2 1   2 0   6 3   3 5   0 1   7 6
  1 5   4 3   4 6   3 0   6 4   5 2   2 0   6 7   2 4   2 0
  3 6   7 5   1 4   7 3   3 2   2 0   3 2   1 3   0 1   7 4
  1 5   5 2   2 6   5 2   6 4   7 6   6 4   4 7   3 5   6 2

Crossrefs

Column 1 of A234911.

Sequence in context: A207075 A242039 A234911 * A187178 A233724 A233718

Adjacent sequences: A234902 A234903 A234904 * A234906 A234907 A234908

Keyword

nonn

Author

R. H. Hardin, Jan 01 2014

Status

approved