A235083 Number of (n+1) X (4+1) 0..4 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).

478, 930, 1758, 3558, 7046, 14702, 29970, 63862, 132746, 287122, 605338, 1324402, 2823950, 6237794, 13432462, 29925830, 65041174, 146070222, 320349666, 724993878, 1604290682, 3657668498, 8165829930, 18749536114, 42223278878

Offset

1,1

Links

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

Formula

Empirical: a(n) = 6*a(n-1) +4*a(n-2) -87*a(n-3) +90*a(n-4) +450*a(n-5) -830*a(n-6) -936*a(n-7) +2737*a(n-8) +408*a(n-9) -4078*a(n-10) +891*a(n-11) +2766*a(n-12) -816*a(n-13) -904*a(n-14) +180*a(n-15) +120*a(n-16).

Example

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

Crossrefs

Column 4 of A235087.

Sequence in context: A020375 A031788 A252543 * A252544 A252545 A260204

Adjacent sequences: A235080 A235081 A235082 * A235084 A235085 A235086

Keyword

nonn

Author

R. H. Hardin, Jan 03 2014

Status

approved