A200054 Number of -5..5 arrays x(0..n-1) of n elements with zero sum and elements alternately strictly increasing and strictly decreasing.

1, 10, 56, 324, 1948, 11962, 74338, 466548, 2947742, 18746754, 119701782, 767860824, 4938868628, 31876070432, 206122332340, 1336425077996, 8676994345132, 56457974059982, 367738443114696, 2399500033305708

Offset: 1

Author

R. H. Hardin Nov 13 2011

Keywords

• nonn

Comments

Column 5 of A200057

Examples

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

Links

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