A235294 Number of (n+1) X (4+1) 0..3 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3 (constant-stress 1 X 1 tilings).

744, 1132, 1736, 3184, 5784, 12328, 25592, 60856, 138744, 356632, 864056, 2342104, 5889144, 16525528, 42475832, 121851736, 317293944, 923151832, 2422801976, 7113966424, 18762768504, 55430893528, 146666831672, 435125968216

Offset

1,1

Links

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

Formula

Empirical: a(n) = 3*a(n-1) + 17*a(n-2) - 57*a(n-3) - 86*a(n-4) + 372*a(n-5) + 76*a(n-6) - 972*a(n-7) + 360*a(n-8) + 864*a(n-9) - 576*a(n-10).

Empirical g.f.: 4*x*(186 - 275*x - 3577*x^2 + 5285*x^3 + 23807*x^4 - 34904*x^5 - 64146*x^6 + 92340*x^7 + 59328*x^8 - 82944*x^9) / ((1 - x)*(1 - 2*x)*(1 - 2*x^2)*(1 - 3*x^2)*(1 - 6*x^2)*(1 - 8*x^2)). - Colin Barker, Oct 18 2018

Example

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

Crossrefs

Column 4 of A235301.

Sequence in context: A345547 A345800 A331092 * A331674 A235252 A268891

Adjacent sequences: A235291 A235292 A235293 * A235295 A235296 A235297

Keyword

nonn

Author

R. H. Hardin, Jan 05 2014

Status

approved