A234222 Number of (n+1) X (3+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3 (constant-stress 1 X 1 tilings).

1824, 5612, 17448, 56936, 188040, 648536, 2264904, 8215256, 30142344, 114224792, 436849608, 1716521816, 6787144200, 27449810456, 111385692744, 460731399896, 1906999712904, 8026422662552, 33728591085768, 143889611473496

Offset

1,1

Links

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

Formula

Empirical: a(n) = 9*a(n-1) +20*a(n-2) -390*a(n-3) +460*a(n-4) +5520*a(n-5) -14240*a(n-6) -26400*a(n-7) +115776*a(n-8) -13824*a(n-9) -299520*a(n-10) +276480*a(n-11).

Example

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

Crossrefs

Column 3 of A234227.

Sequence in context: A256076 A179581 A230052 * A233813 A249536 A124073

Adjacent sequences: A234219 A234220 A234221 * A234223 A234224 A234225

Keyword

nonn

Author

R. H. Hardin, Dec 21 2013

Status

approved