A235011 Number of (n+1) X (2+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).

104, 224, 488, 1112, 2568, 6088, 14600, 35560, 87368, 216680, 540680, 1356968, 3419592, 8648296, 21929864, 55731496, 141870920, 361640936, 922818824, 2356779176, 6022859976, 15399604072, 39390323336, 100787331112, 257945856584

Offset

1,1

Links

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

Formula

Empirical: a(n) = 3*a(n-1) + 4*a(n-2) - 14*a(n-3) - 4*a(n-4) + 16*a(n-5).

Empirical g.f.: 8*x*(13 - 11*x - 75*x^2 + 26*x^3 + 104*x^4) / ((1 - 2*x)*(1 - 2*x^2)*(1 - x - 4*x^2)). - Colin Barker, Oct 16 2018

Example

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

Crossrefs

Column 2 of A235017.

Sequence in context: A108665 A258549 A121962 * A271745 A046298 A298325

Adjacent sequences: A235008 A235009 A235010 * A235012 A235013 A235014

Keyword

nonn

Author

R. H. Hardin, Jan 02 2014

Status

approved