A199650 Number of nX3 0..2 arrays with values 0..2 introduced in row major order and each element equal to no more than two horizontal and vertical neighbors

5, 113, 2584, 59212, 1357484, 31120632, 713445976, 16355879648, 374961537040, 8596061907680, 197066293538400, 4517780870646656, 103570953858672192, 2374383085485820032, 54433167085958461312, 1247890324488906825728

Offset

1,1

Comments

Column 3 of A199655

Links

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

Formula

Empirical: a(n) = 21*a(n-1) +44*a(n-2) +8*a(n-3) -96*a(n-4) -364*a(n-5) -264*a(n-6) +256*a(n-7) +288*a(n-8) +64*a(n-9) for n>10

Example

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

Crossrefs

Sequence in context: A224897 A086805 A163014 * A241109 A208317 A279836

Adjacent sequences: A199647 A199648 A199649 * A199651 A199652 A199653

Keyword

nonn

Author

R. H. Hardin Nov 08 2011

Status

approved