A233153 Number of n X 6 0..2 arrays with no element x(i,j) adjacent to value 2-x(i,j) horizontally or antidiagonally.

96, 1944, 40392, 842616, 17587584, 367125912, 7663517136, 159971190624, 3339300422232, 69705848287656, 1455066835631064, 30373627879088352, 634030855481713176, 13235005291610993904, 276272619155126818272

Offset

1,1

Links

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

Formula

Empirical: a(n) = 25*a(n-1) - 90*a(n-2) + 81*a(n-3).

Empirical g.f.: 24*x*(4 - 19*x + 18*x^2) / (1 - 25*x + 90*x^2 - 81*x^3). - Colin Barker, Oct 08 2018

Example

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

Crossrefs

Column 6 of A233155.

Sequence in context: A093984 A159711 A268636 * A204624 A090449 A336677

Adjacent sequences: A233150 A233151 A233152 * A233154 A233155 A233156

Keyword

nonn

Author

R. H. Hardin, Dec 05 2013

Status

approved