A199702 Number of -6..6 arrays x(0..n-1) of n elements with zero sum and no two neighbors equal

1, 12, 114, 1236, 13324, 147072, 1643204, 18527516, 210316392, 2400684208, 27527644696, 316844861020, 3658598730648, 42361908912360, 491666143730354, 5718341649577364, 66629811252553344, 777637357808739752

Offset

1,2

Comments

Column 6 of A199704

Links

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

Example

Some solutions for n=5
.-3....0...-4...-3....0....1...-3....3....4....1....6...-1....6...-4....4...-3
..0...-1....4....6...-2...-2....3....0....2...-1...-1...-5...-2....2...-6....6
..2....5....0...-6....2....0....5...-4....3....0....1...-2...-3....0...-1...-3
..3...-1...-4....3....5....6...-4....4...-6...-3...-2....3....4....3....1....5
.-2...-3....4....0...-5...-5...-1...-3...-3....3...-4....5...-5...-1....2...-5

Crossrefs

Sequence in context: A080602 A333299 A090250 * A307820 A154247 A016204

Adjacent sequences: A199699 A199700 A199701 * A199703 A199704 A199705

Keyword

nonn

Author

R. H. Hardin Nov 09 2011

Status

approved