A188228 Number of nondecreasing arrangements of n numbers in -(n-1)..(n-1) with sum zero and not more than two numbers equal.

1, 2, 4, 15, 58, 245, 1082, 5020, 24040, 118154, 592332, 3019280, 15604848, 81614541, 431227650, 2298833499, 12350952158, 66818754504, 363727676848, 1990946917066, 10952512200610, 60525264890259, 335856363303010, 1870732844007387

Offset: 1

Author

R. H. Hardin Mar 24 2011

Keywords

• nonn

Comments

Column 1 of A188236

Examples

			All solutions for n=4
.-3...-1...-2...-3...-3...-2...-1...-2...-3...-2...-3...-1...-2...-2...-3
.-1...-1....0....0...-2...-2...-1...-2...-3....0....0....0...-1...-1...-1
..1....0....1....1....2....1....1....2....3....0....0....0....0....1....2
..3....2....1....2....3....3....1....2....3....2....3....1....3....2....2
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..31