A235086 Number of (n+1) X (7+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).

5786, 9838, 16390, 29970, 53882, 103702, 196302, 390578, 764386, 1553646, 3106158, 6403898, 12986378, 27053230, 55429622, 116456530, 240620906, 509472502, 1060761214, 2263211058, 4748262482, 10211045710, 21595163358, 46827642938

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

Crossrefs

Column 7 of A235087.

Sequence in context: A004953 A004973 A114361 * A098476 A248132 A238553

Adjacent sequences: A235083 A235084 A235085 * A235087 A235088 A235089

Keyword

nonn

Author

R. H. Hardin, Jan 03 2014

Status

approved