A200056 Number of -7..7 arrays x(0..n-1) of n elements with zero sum and elements alternately strictly increasing and strictly decreasing.

1, 14, 106, 850, 7074, 59910, 514168, 4453946, 38855488, 341052122, 3006680636, 26619825378, 236386648574, 2105717447626, 18798362729604, 168222072625668, 1507848061916274, 13541292792666004, 121763260320351938

Offset

1,2

Comments

Column 7 of A200057

Links

R. H. Hardin, Table of n, a(n) for n = 1..189

Example

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

Crossrefs

Sequence in context: A190868 A125351 A126509 * A206754 A099300 A038735

Adjacent sequences: A200053 A200054 A200055 * A200057 A200058 A200059

Keyword

nonn

Author

R. H. Hardin, Nov 13 2011

Status

approved