A234659 Number of (n+1) X (1+1) 0..6 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4 (constant-stress 1 X 1 tilings).

298, 1820, 11112, 68086, 417050, 2564388, 15760606, 97264082, 599847168, 3715680490, 22995724082, 142980376236, 887988916630, 5541920176778, 34537856122656, 216342520763602, 1352830192028858, 8504211973522620

Offset

1,1

Links

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

Formula

Empirical: a(n) = 11*a(n-1) + 17*a(n-2) - 492*a(n-3) + 1050*a(n-4) + 1260*a(n-5).

Empirical g.f.: 2*x*(149 - 729*x - 6987*x^2 + 30765*x^3 + 30870*x^4) / ((1 - 6*x)*(1 - 5*x - 5*x^2)*(1 - 42*x^2)). - Colin Barker, Oct 16 2018

Example

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

Crossrefs

Column 1 of A234665.

Sequence in context: A200218 A284156 A234665 * A186126 A129037 A249296

Adjacent sequences: A234656 A234657 A234658 * A234660 A234661 A234662

Keyword

nonn

Author

R. H. Hardin, Dec 29 2013

Status

approved