A234258 Number of (n+1) X (n+1) 0..2 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 2 (constant-stress 1 X 1 tilings).

20, 88, 292, 988, 3188, 11140, 39508, 147892, 562580, 2191828, 8605972, 34091668, 135464468, 539959060, 2154718228, 8607898132

Offset

1,1

Links

Table of n, a(n) for n=1..16.

Example

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

Crossrefs

Diagonal of A234266.

Sequence in context: A339343 A306987 A249983 * A213839 A264302 A220200

Adjacent sequences: A234255 A234256 A234257 * A234259 A234260 A234261

Keyword

nonn

Author

R. H. Hardin, Dec 22 2013

Status

approved