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

Author

R. H. Hardin Nov 13 2011

Keywords

• nonn

Comments

Column 7 of A200057

Examples

			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
		

Links

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