A188114 Number of strictly increasing arrangements of n nonzero numbers in -(n-1)..(n-1) with sum zero

0, 1, 0, 3, 4, 16, 42, 137, 426, 1398, 4622, 15594, 53252, 184060, 642392, 2261829, 8024726, 28664946, 103015222, 372234190, 1351655526, 4930080182, 18055480464, 66371559466, 244817099870, 905883648170, 3361795172242, 12509691344838

Offset

1,4

Comments

Column 1 of A188122

Links

R. H. Hardin, Table of n, a(n) for n = 1..32

Example

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

Crossrefs

Equals A188116(n-2)

Sequence in context: A330693 A329541 A154736 * A188116 A300316 A329546

Adjacent sequences: A188111 A188112 A188113 * A188115 A188116 A188117

Keyword

nonn

Author

R. H. Hardin Mar 21 2011

Status

approved