A188174 Number of strictly increasing arrangements of n numbers in -(2n-2)..(2n-2) with sum zero

1, 2, 8, 43, 252, 1636, 11322, 81805, 610358, 4672836, 36525052, 290399543, 2342043630, 19118822650, 157709971144, 1312796873451, 11015236989702, 93078467831012, 791462018168032, 6767910089071288, 58167781282121262

Offset

1,2

Comments

Diagonal of A188181

Links

R. H. Hardin, Table of n, a(n) for n = 1..32

Example

Some solutions for n=5
.-8...-7...-4...-6...-6...-7...-8...-8...-5...-5...-7...-6...-5...-7...-4...-7
.-6...-4...-2...-5...-5...-2...-1...-3...-2...-2...-5...-4...-3...-3...-3...-4
.-1....1....0...-3....1....1....0...-1...-1...-1....0...-1...-1....2...-1....1
..7....4....2....6....3....3....1....5....0....1....4....3....3....3....3....2
..8....6....4....8....7....5....8....7....8....7....8....8....6....5....5....8

Crossrefs

Sequence in context: A012917 A050637 A349145 * A193659 A020023 A027836

Adjacent sequences: A188171 A188172 A188173 * A188175 A188176 A188177

Keyword

nonn

Author

R. H. Hardin Mar 23 2011

Status

approved