A188177 Number of strictly increasing arrangements of n numbers in -(n+3)..(n+3) with sum zero

1, 5, 18, 69, 252, 920, 3370, 12346, 45207, 165821, 609734, 2247151, 8300708, 30734578, 114067100, 424306230, 1581788460, 5909243454, 22120325320, 82963636468, 311732564498, 1173377033602, 4424032482238, 16706682557212

Offset

1,2

Comments

Column 5 of A188181

Links

R. H. Hardin, Table of n, a(n) for n = 1..28

Example

Some solutions for n=6
.-8...-8...-9...-8...-9...-8...-9...-6...-9...-8...-4...-9...-4...-9...-8...-8
.-4...-7...-1...-3...-2...-7...-3...-2...-3...-7...-3...-8...-3...-6...-5...-3
.-3...-1....0...-2....0...-4...-2...-1...-1...-3...-2....0...-2....1...-3...-1
.-1....4....1....0....1....2....2....0....3....2....2....3...-1....3....0....0
..7....5....3....5....2....8....5....1....4....7....3....6....3....5....7....5
..9....7....6....8....8....9....7....8....6....9....4....8....7....6....9....7

Crossrefs

Sequence in context: A109438 A164051 A134764 * A343490 A302077 A322773

Adjacent sequences: A188174 A188175 A188176 * A188178 A188179 A188180

Keyword

nonn

Author

R. H. Hardin Mar 23 2011

Status

approved