A231058 Number of n X 3 0..3 arrays x(i,j) with each element horizontally or vertically next to at least one element with value (x(i,j)+1) mod 4, no adjacent elements equal, and upper left element zero.

0, 6, 34, 208, 1272, 7818, 47998, 294832, 1810916, 11123242, 68322370, 419657160, 2577663664, 15832804586, 97249963694, 597339237368, 3669041620356, 22536383966338, 138425413185266, 850251533001856, 5222506855786032

Offset

1,2

Comments

Column 3 of A231063.

Links

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

Formula

Empirical: a(n) = 8*a(n-1) -9*a(n-2) -20*a(n-3) +29*a(n-4) +22*a(n-5) -23*a(n-6) -14*a(n-7) -14*a(n-8) +4*a(n-9) +2*a(n-10).

Example

Some solutions for n=4
..0..3..0....0..3..2....0..1..2....0..3..2....0..3..2....0..1..2....0..3..2
..1..2..1....1..2..1....1..0..3....1..2..1....1..2..1....3..0..3....1..0..3
..2..3..0....0..1..0....2..3..2....2..1..0....0..3..0....2..1..0....2..3..2
..1..2..3....3..0..3....1..0..1....3..0..3....3..2..1....3..0..3....1..2..1

Crossrefs

Cf. A231063.

Sequence in context: A244829 A059228 A079568 * A317178 A218893 A266431

Adjacent sequences: A231055 A231056 A231057 * A231059 A231060 A231061

Keyword

nonn

Author

R. H. Hardin, Nov 03 2013

Status

approved