A234483 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 2 (constant-stress 1 X 1 tilings).

62, 242, 944, 3686, 14402, 56312, 220334, 862706, 3380192, 13252982, 51996674, 204137576, 801957182, 3152502002, 12400248464, 48805735046, 192207885122, 757400598872, 2986264405454, 11780750826866, 46500068952512

Offset

1,1

Links

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

Formula

Empirical: a(n) = 7*a(n-1) - 9*a(n-2) - 12*a(n-3).

Empirical g.f.: 2*x*(31 - 96*x - 96*x^2) / ((1 - 4*x)*(1 - 3*x - 3*x^2)). - Colin Barker, Oct 15 2018

Example

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

Crossrefs

Column 1 of A234490.

Sequence in context: A230007 A318561 A234490 * A158067 A045220 A100158

Adjacent sequences: A234480 A234481 A234482 * A234484 A234485 A234486

Keyword

nonn

Author

R. H. Hardin, Dec 26 2013

Status

approved