A201809 Number of arrays of n integers in -6..6 with sum zero and equal numbers of elements greater than zero and less than zero

1, 13, 37, 949, 4501, 99961, 637393, 12004357, 93039589, 1554288913, 13794790153, 211729119889, 2069010499921, 29916152015413, 313278539674477, 4343800080821797, 47825160489621541, 643987273822751329

Offset

1,2

Comments

Column 6 of A201811

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Example

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

Crossrefs

Sequence in context: A195540 A262475 A309808 * A129541 A302858 A244185

Adjacent sequences: A201806 A201807 A201808 * A201810 A201811 A201812

Keyword

nonn

Author

R. H. Hardin Dec 05 2011

Status

approved