A235276 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 5 (constant-stress 1 X 1 tilings).

2800, 3844, 5096, 7936, 11704, 20440, 33464, 64168, 115480, 238024, 463736, 1009096, 2091544, 4737160, 10277624, 23969608, 53719960, 127968904, 293325176, 709379656, 1651106584, 4035596680, 9490235384, 23366392648, 55327897240

Offset

1,1

Links

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

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).

Empirical g.f.: 4*x*(700 + 261*x - 10187*x^2 - 3205*x^3 + 52247*x^4 + 12414*x^5 - 111834*x^6 - 15264*x^7 + 83808*x^8) / ((1 - x)*(1 - 2*x)*(1 + 2*x)*(1 - 2*x^2)*(1 - 3*x^2)*(1 - 6*x^2)). - Colin Barker, Oct 18 2018

Example

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

Crossrefs

Column 6 of A235280.

Sequence in context: A236943 A236777 A210104 * A115471 A292011 A306849

Adjacent sequences: A235273 A235274 A235275 * A235277 A235278 A235279

Keyword

nonn

Author

R. H. Hardin, Jan 05 2014

Status

approved