A234136 Number of (n+1) X (4+1) 0..3 arrays with every 2 X 2 subblock having the sum of the absolute values of all six edge and diagonal differences equal to 9.

512, 680, 968, 1640, 2984, 6440, 14120, 35624, 86312, 236840, 602408, 1726760, 4497704, 13185320, 34750760, 103047464, 273187112, 814793000, 2166423848, 6480298280, 17255498024, 51690799400, 137741205800, 412921233704

Offset

1,1

Links

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

Formula

Empirical: a(n) = 3*a(n-1) + 8*a(n-2) - 30*a(n-3) + 4*a(n-4) + 48*a(n-5) - 32*a(n-6).

Empirical g.f.: 8*x*(64 - 107*x - 646*x^2 + 1082*x^3 + 1084*x^4 - 1736*x^5) / ((1 - x)*(1 - 2*x)*(1 - 2*x^2)*(1 - 8*x^2)). - Colin Barker, Oct 13 2018

Example

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

Crossrefs

Column 4 of A234140.

Sequence in context: A217849 A326113 A045003 * A248536 A202461 A046311

Adjacent sequences: A234133 A234134 A234135 * A234137 A234138 A234139

Keyword

nonn

Author

R. H. Hardin, Dec 19 2013

Status

approved