A199701 Number of -5..5 arrays x(0..n-1) of n elements with zero sum and no two neighbors equal

1, 10, 82, 724, 6504, 59992, 559028, 5252900, 49700882, 472873888, 4519281222, 43353372676, 417214414596, 4026070558436, 38943205468034, 377469980604452, 3665456335373858, 35651726951195532, 347268836196275908

Offset

1,2

Comments

Column 5 of A199704

Links

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

Example

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

Crossrefs

Sequence in context: A037549 A238276 A287825 * A103460 A339689 A238843

Adjacent sequences: A199698 A199699 A199700 * A199702 A199703 A199704

Keyword

nonn

Author

R. H. Hardin Nov 09 2011

Status

approved