A188120 Number of strictly increasing arrangements of n nonzero numbers in -(n+5)..(n+5) with sum zero

0, 7, 24, 118, 482, 1999, 8044, 32035, 126122, 493267, 1918884, 7436318, 28736532, 110822456, 426763772, 1641751842, 6311555602, 24254371734, 93187581596, 358022612486, 1375631211812, 5286588768343, 20321901846262, 78143777698585

Offset

1,2

Comments

Column 7 of A188122

Links

R. H. Hardin, Table of n, a(n) for n = 1..26

Example

Some solutions for n=6
.-7..-10...-9...-6...-5..-11..-11..-11...-9...-6..-11...-7..-11...-8...-7...-8
.-4...-5...-7...-5...-3...-9...-7...-7...-6...-4...-5...-6...-6...-3...-4...-5
.-3...-3...-3...-4...-2...-5...-1...-5...-3...-1...-4...-2...-1...-2...-3...-1
..3....3....2...-1...-1....7....2....4...-1....1....3...-1....3...-1....2....1
..4....4....8....7....3....8....7....9....9....3....7....5....6....5....4....6
..7...11....9....9....8...10...10...10...10....7...10...11....9....9....8....7

Crossrefs

Sequence in context: A321390 A283457 A129797 * A007750 A153577 A009643

Adjacent sequences: A188117 A188118 A188119 * A188121 A188122 A188123

Keyword

nonn

Author

R. H. Hardin Mar 21 2011

Status

approved