A200055 Number of -6..6 arrays x(0..n-1) of n elements with zero sum and elements alternately strictly increasing and strictly decreasing.

1, 12, 78, 546, 3914, 28554, 211242, 1577878, 11867186, 89815404, 682642050, 5211283212, 39897460856, 306446600454, 2358644800468, 18199380449274, 140644480480176, 1089068472750998, 8443172123261506, 65564035662489652

Offset: 1

Author

R. H. Hardin Nov 13 2011

Keywords

• nonn

Comments

Column 6 of A200057

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..200