A184378 1/12 the number of (n+2) X 3 0..2 arrays with each 3 X 3 subblock containing three of each value.

140, 545, 2174, 9113, 43295, 212747, 1096781, 6045233, 33958643, 194694395, 1141026791, 6726497945, 39885267065, 237890735825, 1421015749799, 8500910306963, 50929911923495, 305241246279617, 1830098075374121

Offset

1,1

Comments

Column 1 of A184386.

Links

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

Formula

Empirical: a(n) = 10*a(n-1)-27*a(n-2)+81*a(n-3)-630*a(n-4)+1701*a(n-5)-1620*a(n-6)+4860*a(n-7)-13122*a(n-8)+8748*a(n-9).

Example

Some solutions with a(1,1)=0 for 4 X 3
..0..2..2....0..2..0....0..2..2....0..2..1....0..2..1....0..0..0....0..0..2
..1..1..2....2..1..1....0..1..1....0..1..2....1..0..0....2..2..2....1..2..2
..1..0..0....0..2..1....0..2..1....0..2..1....1..2..2....1..1..1....0..1..1
..2..2..0....0..2..0....2..2..0....2..0..1....2..0..1....0..0..0....2..0..0

Crossrefs

Cf. A184386.

Sequence in context: A350210 A250801 A184386 * A180294 A330446 A317984

Adjacent sequences: A184375 A184376 A184377 * A184379 A184380 A184381

Keyword

nonn

Author

R. H. Hardin, Jan 12 2011

Status

approved