A234652 Number of (n+1) X (2+1) 0..5 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4 (constant-stress 1 X 1 tilings).

728, 2648, 9616, 37352, 144512, 593048, 2414992, 10359416, 43905728, 194994488, 851994256, 3886321592, 17372570432, 80869715768, 367672598032, 1738035049016, 8001387470528, 38267054762168, 177809954398096, 857989731643832

Offset

1,1

Links

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

Formula

Empirical: a(n) = 9*a(n-1) +59*a(n-2) -741*a(n-3) -680*a(n-4) +23970*a(n-5) -24980*a(n-6) -382080*a(n-7) +836736*a(n-8) +3002976*a(n-9) -9941184*a(n-10) -8688384*a(n-11) +53360640*a(n-12) -15759360*a(n-13) -107827200*a(n-14) +99532800*a(n-15).

Example

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

Crossrefs

Column 2 of A234658.

Sequence in context: A043487 A158395 A184077 * A050219 A051383 A293650

Adjacent sequences: A234649 A234650 A234651 * A234653 A234654 A234655

Keyword

nonn

Author

R. H. Hardin, Dec 29 2013

Status

approved