A233078 Number of n X 4 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally or antidiagonally, top left element zero, and 1 appearing before 2 in row major order.

14, 662, 32414, 1588262, 77824814, 3813415862, 186857377214, 9156011483462, 448644562689614, 21983583571791062, 1077195595017762014, 52782584155870338662, 2586346623637646594414, 126730984558244683126262

Offset

1,1

Links

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

Formula

Empirical: a(n) = 50*a(n-1) - 49*a(n-2).

Conjectures from Colin Barker, Oct 07 2018: (Start)

G.f.: 2*x*(7 - 19*x) / ((1 - x)*(1 - 49*x)).

a(n) = (49 + 27*49^n) / 98.

(End)

Example

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

Crossrefs

Column 4 of A233082.

Sequence in context: A210808 A139196 A336513 * A223129 A303288 A277299

Adjacent sequences: A233075 A233076 A233077 * A233079 A233080 A233081

Keyword

nonn

Author

R. H. Hardin, Dec 03 2013

Status

approved