A234485 Number of (n+1) X (3+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).

944, 3540, 13260, 49784, 187196, 705072, 2659824, 10049936, 38030588, 144134184, 547062036, 2079436784, 7915312712, 30172181304, 115169444940, 440212045280, 1684837886252, 6456944580816, 24776948509056, 95196417683360

Offset

1,1

Links

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

Formula

Empirical: a(n) = 13*a(n-1) -43*a(n-2) -107*a(n-3) +865*a(n-4) -1033*a(n-5) -1916*a(n-6) +2822*a(n-7) +2712*a(n-8) -1332*a(n-9) -1512*a(n-10) -288*a(n-11).

Example

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

Crossrefs

Column 3 of A234490.

Sequence in context: A252294 A268268 A106431 * A260136 A215838 A145493

Adjacent sequences: A234482 A234483 A234484 * A234486 A234487 A234488

Keyword

nonn

Author

R. H. Hardin, Dec 26 2013

Status

approved