A183647 Number of (n+1) X 5 0..4 arrays with every 2 X 2 subblock summing to 8.

5725, 12785, 33325, 97145, 307525, 1037585, 3684925, 13653545, 52436725, 207712385, 845452525, 3525617945, 15026853925, 65331315185, 289222676125, 1301655470345, 5946166679125, 27529329445985, 128980999355725

Offset

1,1

Comments

Column 4 of A183652.

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 15*a(n-1) - 85*a(n-2) + 225*a(n-3) - 274*a(n-4) + 120*a(n-5).

Empirical g.f.: 5*x*(1145 - 14618*x + 65635*x^2 - 120826*x^3 + 75000*x^4) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 4*x)*(1 - 5*x)). - Colin Barker, Apr 01 2018

Example

Some solutions for 3 X 5:
  3 3 3 3 3    1 2 1 4 2    0 4 0 3 0    1 4 0 3 3
  0 2 0 2 0    1 4 1 2 0    3 1 3 2 3    2 1 3 2 0
  2 4 2 4 2    2 1 2 3 3    1 3 1 2 1    2 3 1 2 4

Crossrefs

Cf. A183652.

Sequence in context: A202376 A330208 A252422 * A028547 A224726 A378491

Adjacent sequences: A183644 A183645 A183646 * A183648 A183649 A183650

Keyword

nonn

Author

R. H. Hardin, Jan 06 2011

Status

approved