A183638 Number of (n+1) X 6 0..3 arrays with every 2 X 2 subblock summing to 6.

5684, 9256, 17612, 38056, 90524, 231736, 629132, 1793416, 5328764, 16413016, 52195052, 170891176, 574845404, 1983103096, 7003319372, 25265467336, 92897360444, 347253741976, 1316323506092, 5047850897896, 19540336713884

Offset

1,1

Comments

Column 5 of A183642.

Links

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

Formula

Empirical: a(n) = 10*a(n-1) - 35*a(n-2) + 50*a(n-3) - 24*a(n-4).

Conjectures from Colin Barker, Mar 31 2018: (Start)

G.f.: 4*x*(1421 - 11896*x + 30998*x^2 - 24576*x^3) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 4*x)).

a(n) = 2702 + 301*2^(2+n) + 62*3^(1+n) + 4^(1+n).

(End)

Example

Some solutions for 3 X 6:
  2 0 1 2 3 0    2 1 2 3 1 1    1 1 1 1 1 1    2 3 3 3 1 0
  1 3 2 1 0 3    1 2 1 0 2 2    3 1 3 1 3 1    1 0 0 0 2 3
  1 1 0 3 2 1    2 1 2 3 1 1    0 2 0 2 0 2    2 3 3 3 1 0

Crossrefs

Cf. A183642.

Sequence in context: A224690 A224683 A222824 * A192098 A287239 A204532

Adjacent sequences: A183635 A183636 A183637 * A183639 A183640 A183641

Keyword

nonn

Author

R. H. Hardin, Jan 06 2011

Status

approved