A188205 Number of nondecreasing arrangements of n numbers in -(n+1)..(n+1) with sum zero.

1, 4, 13, 55, 252, 1242, 6375, 33885, 184717, 1028172, 5820904, 33427622, 194299052, 1141190188, 6763576681, 40405993509, 243090678343, 1471673620504, 8959718123381, 54824825183377, 337018924981048, 2080401423880834

Offset: 1

Author

R. H. Hardin Mar 24 2011

Keywords

• nonn

Comments

Column 3 of A188211

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..30