A234228 Number of (n+1) X (1+1) 0..7 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3 (constant-stress 1 X 1 tilings).

568, 5260, 48592, 449880, 4160672, 38547120, 356781376, 3308068320, 30642026624, 284343188160, 2635852305664, 24479566880640, 227101552312832, 2110876497027840, 19598341417366528, 182315530807365120

Offset

1,1

Links

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

Formula

Empirical: a(n) = 182*a(n-2) - 9024*a(n-4) + 66960*a(n-6).

Empirical g.f.: 4*x*(142 + 1315*x - 13696*x^2 - 126860*x^3 + 110640*x^4 + 1033800*x^5) / ((1 - 90*x^2)*(1 - 92*x^2 + 744*x^4)). - Colin Barker, Oct 14 2018

Example

Some solutions for n=3:
  2 4   5 2   7 6   7 4   7 0   2 3   7 3   6 2   0 1   2 4
  3 2   0 0   7 3   0 0   7 3   3 1   1 0   5 4   2 0   6 5
  2 4   3 6   1 0   5 2   3 2   6 1   2 4   5 7   2 3   2 4
  1 0   1 7   2 4   3 3   4 0   6 4   6 5   5 4   2 0   2 7

Crossrefs

Column 1 of A234233.

Sequence in context: A134922 A322688 A234233 * A184682 A223164 A290868

Adjacent sequences: A234225 A234226 A234227 * A234229 A234230 A234231

Keyword

nonn

Author

R. H. Hardin, Dec 21 2013

Status

approved