A199841 Number of -2..2 arrays x(0..n-1) of n elements with zero sum and no element more than one greater than the previous

1, 3, 8, 23, 66, 192, 575, 1739, 5307, 16304, 50381, 156408, 487398, 1523663, 4776107, 15006513, 47247134, 149023605, 470794024, 1489462276, 4718330397, 14964219411, 47509518289, 150982994162, 480243297965, 1528796563830, 4870415108094

Offset

1,2

Comments

Column 2 of A199847

Links

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

Example

Some solutions for n=6
..2...-1....2....1....2....1....1....1....1...-1....2....1....1....1....1....1
..1....0....0...-1....1....1....2....1...-1....0....2....1....1....2....0....0
.-2....1....1....0....2....0....0....0...-1....1...-2....1....1....1....0...-1
.-1....0...-2....0...-1...-1....0....1....0....1...-1....0...-1...-1....0....0
..0....1...-1....0...-2....0...-2...-2....0....1...-1...-1....0...-1....1....0
..0...-1....0....0...-2...-1...-1...-1....1...-2....0...-2...-2...-2...-2....0

Crossrefs

Sequence in context: A291037 A147704 A116410 * A106606 A050535 A025578

Adjacent sequences: A199838 A199839 A199840 * A199842 A199843 A199844

Keyword

nonn

Author

R. H. Hardin Nov 11 2011

Status

approved