A235101 Number of (n+1) X (2+1) 0..6 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).

670, 2498, 9328, 35354, 135254, 523532, 2047890, 8097130, 32339728, 130423938, 530742334, 2177937580, 9005319178, 37492012258, 157045852768, 661404560282, 2798723937382, 11891816958860, 50708771987330, 216898348529434

Offset

1,1

Links

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

Formula

Empirical: a(n) = 12*a(n-1) -14*a(n-2) -322*a(n-3) +949*a(n-4) +3384*a(n-5) -12901*a(n-6) -21740*a(n-7) +86236*a(n-8) +107744*a(n-9) -322761*a(n-10) -412538*a(n-11) +641088*a(n-12) +1018740*a(n-13) -478292*a(n-14) -1306432*a(n-15) -247248*a(n-16) +584736*a(n-17) +372096*a(n-18) +65664*a(n-19).

Example

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

Crossrefs

Column 2 of A235107.

Sequence in context: A067875 A224558 A250670 * A232388 A172963 A351668

Adjacent sequences: A235098 A235099 A235100 * A235102 A235103 A235104

Keyword

nonn

Author

R. H. Hardin, Jan 03 2014

Status

approved