A183636 Number of (n+1) X 4 0..3 arrays with every 2 X 2 subblock summing to 6.

452, 952, 2300, 6136, 17612, 53512, 170300, 563416, 1926572, 6776872, 24422300, 89839096, 336216332, 1276265032, 4900898300, 18994385176, 74156470892, 291175781992, 1148379038300, 4544596313656, 18031730594252, 71687168111752

Offset

1,1

Comments

Column 3 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*(113 - 892*x + 2150*x^2 - 1536*x^3) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 4*x)).

a(n) = 110 + 25*2^(2+n) + 14*3^(1+n) + 4^(1+n).

(End)

Example

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

Crossrefs

Cf. A183642.

Sequence in context: A224568 A224561 A116308 * A222823 A205209 A236665

Adjacent sequences: A183633 A183634 A183635 * A183637 A183638 A183639

Keyword

nonn

Author

R. H. Hardin, Jan 06 2011

Status

approved