A188227 Number of nondecreasing arrangements of n numbers in -(2n-2)..(2n-2) with sum zero and not more than two numbers equal.

1, 3, 12, 81, 598, 4859, 41748, 374820, 3475284, 33053399, 320869264, 3167899567, 31721907390, 321494911644, 3292220700520, 34018798556265, 354312456839426, 3716173628641396, 39220841304052510, 416264662788000213

Offset

1,2

Comments

Diagonal of A188236

Links

R. H. Hardin, Table of n, a(n) for n = 1..22

Example

Some solutions for n=4
.-1...-3...-3...-3...-4...-5...-6...-5...-4...-5...-3...-3...-2...-6...-2...-4
.-1....0...-2...-1...-1...-2...-1....0....1...-1...-1...-3...-2...-4...-1...-4
..1....1....0....1...-1....1....2....2....1....2....2....3....2....4....0....2
..1....2....5....3....6....6....5....3....2....4....2....3....2....6....3....6

Crossrefs

Sequence in context: A197445 A303033 A207322 * A396793 A357665 A224608

Adjacent sequences: A188224 A188225 A188226 * A188228 A188229 A188230

Keyword

nonn

Author

R. H. Hardin, Mar 24 2011

Status

approved