A188119 Number of strictly increasing arrangements of n nonzero numbers in -(n+4)..(n+4) with sum zero

0, 6, 18, 80, 296, 1154, 4376, 16547, 62222, 233880, 878268, 3297368, 12383528, 46541138, 175070668, 659220634, 2485025556, 9378589340, 35437315784, 134061346668, 507765754320, 1925456658954, 7309793143626, 27782162090527

Offset

1,2

Comments

Column 6 of A188122

Links

R. H. Hardin, Table of n, a(n) for n = 1..27

Example

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

Crossrefs

Sequence in context: A299412 A218080 A277609 * A239420 A219590 A260664

Adjacent sequences: A188116 A188117 A188118 * A188120 A188121 A188122

Keyword

nonn

Author

R. H. Hardin Mar 21 2011

Status

approved