A235278 Number of (n+1) X (8+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 5 (constant-stress 1 X 1 tilings).

15520, 19060, 23000, 31504, 41704, 64168, 93992, 160888, 260680, 487960, 867560, 1744024, 3354184, 7125208, 14577512, 32303128, 69232840, 158470360, 351398120, 824485144, 1873576264, 4478463448, 10354825832, 25091436568, 58718701000

Offset

1,1

Comments

Column 8 of A235280.

Links

R. H. Hardin, Table of n, a(n) for n = 1..109

Formula

Empirical: a(n) = a(n-1) +15*a(n-2) -15*a(n-3) -80*a(n-4) +80*a(n-5) +180*a(n-6) -180*a(n-7) -144*a(n-8) +144*a(n-9).

Example

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

Crossrefs

Sequence in context: A035920 A342310 A201344 * A329769 A100973 A247692

Adjacent sequences: A235275 A235276 A235277 * A235279 A235280 A235281

Keyword

nonn

Author

R. H. Hardin, Jan 05 2014

Status

approved