A200052 Number of -3..3 arrays x(0..n-1) of n elements with zero sum and elements alternately strictly increasing and strictly decreasing.

1, 6, 22, 78, 288, 1098, 4224, 16432, 64310, 253692, 1003374, 3992358, 15908668, 63684848, 255153798, 1026057576, 4127971346, 16658240722, 67237254862, 272092306164, 1101134446908, 4466186295698, 18113540529096, 73607652658268, 299074725301088, 1217290931946978

Offset: 1

Author

R. H. Hardin, Nov 13 2011

Keywords

• nonn
• changed

Examples

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

Links

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

Crossrefs

Column 3 of A200057.