A188230 Number of nondecreasing arrangements of n numbers in -(n+1)..(n+1) with sum zero and not more than two numbers equal.

1, 4, 12, 52, 221, 1019, 4818, 23522, 117209, 594789, 3062414, 15966168, 84132345, 447457816, 2399177028, 12956403904, 70416558196, 384897011042, 2114694606220, 11672750655842, 64705139473661, 360068911514032, 2010827078176568

Offset: 1

Author

R. H. Hardin Mar 24 2011

Keywords

• nonn

Comments

Column 3 of A188236

Examples

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

Links

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