A188117 Number of strictly increasing arrangements of n nonzero numbers in -(n+2)..(n+2) with sum zero.

0, 4, 8, 31, 90, 308, 1032, 3528, 12124, 42262, 148518, 525869, 1874648, 6725266, 24260940, 87958188, 320349712, 1171609968, 4301272078, 15846418258, 58569008756, 217121189648, 807123533172, 3008133255026, 11238226082080

Offset: 1

Author

R. H. Hardin Mar 21 2011

Keywords

• nonn

Comments

Column 4 of A188122

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..29