A188328 Number of nondecreasing arrangements of n nonzero numbers in -(n+2)..(n+2) with sum zero

0, 4, 12, 61, 288, 1488, 7836, 42593, 236130, 1333130, 7636298, 44294040, 259682196, 1536666930, 9167492664, 55086510571, 333133752902, 2026193778596, 12387543671686, 76088580071361, 469354099705916, 2906492292139022

Offset

1,2

Comments

Column 4 of A188333

Links

R. H. Hardin, Table of n, a(n) for n = 1..29

Example

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

Crossrefs

Sequence in context: A083484 A088860 A097250 * A291772 A222645 A259816

Adjacent sequences: A188325 A188326 A188327 * A188329 A188330 A188331

Keyword

nonn

Author

R. H. Hardin Mar 28 2011

Status

approved