A235169 Number of (n+1) X (1+1) 0..7 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).

268, 1528, 8688, 49464, 281580, 1603344, 9129276, 51991032, 296077680, 1686409896, 9605163060, 54717521520, 311695967268, 1775889808968, 10117725689808, 57654052582296, 328516960925484, 1872258361831056

Offset

1,1

Links

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

Formula

Empirical: a(n) = 6*a(n-1) +37*a(n-2) -234*a(n-3) -141*a(n-4) +1290*a(n-5) +108*a(n-6) -2340*a(n-7) +1296*a(n-9).

Example

Some solutions for n=4:
  1 7   2 7   3 6   4 3   1 3   2 1   0 7   6 3   0 1   7 2
  4 6   3 4   2 1   1 4   6 4   1 4   2 5   0 1   1 6   5 4
  3 1   0 5   3 6   7 6   4 6   3 2   4 3   1 6   4 5   7 2
  2 4   2 3   5 4   0 3   5 3   6 1   2 5   3 4   5 2   6 5
  0 6   1 6   7 2   2 1   4 6   4 3   1 0   4 1   4 5   3 6

Crossrefs

Column 1 of A235175.

Sequence in context: A237228 A190352 A235175 * A352474 A375334 A330413

Adjacent sequences: A235166 A235167 A235168 * A235170 A235171 A235172

Keyword

nonn

Author

R. H. Hardin, Jan 04 2014

Status

approved