A235085 Number of (n+1) X (6+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).

2554, 4514, 7810, 14702, 27218, 53590, 103702, 210318, 418838, 866298, 1758206, 3687018, 7583258, 16071562, 33396914, 71419678, 149733442, 322890902, 682659526, 1484242286, 3164667686, 6938097082, 14923990510, 32998428714

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:
  0 2 1 3 1 2 0       1 0 2 1 2 1 2       3 4 2 3 2 4 1
  2 0 3 1 3 0 2       0 3 1 4 1 4 1       4 1 3 0 3 1 2
  0 2 1 3 1 2 0       1 0 2 1 2 1 2       3 4 2 3 2 4 1
  2 0 3 1 3 0 2       0 3 1 4 1 4 1       4 1 3 0 3 1 2
  0 2 1 3 1 2 0       3 2 4 3 4 3 4       2 3 1 2 1 3 0
  3 1 4 2 4 1 3       0 3 1 4 1 4 1       4 1 3 0 3 1 2

Crossrefs

Column 6 of A235087.

Sequence in context: A050413 A050544 A185516 * A252685 A255030 A255037

Adjacent sequences: A235082 A235083 A235084 * A235086 A235087 A235088

Keyword

nonn

Author

R. H. Hardin, Jan 03 2014

Status

approved