A200186 Number of -2..2 arrays x(0..n-1) of n elements with zero sum, adjacent elements differing by more than one, and elements alternately increasing and decreasing.

1, 4, 6, 14, 24, 54, 104, 230, 464, 1028, 2128, 4720, 9918, 22038, 46760, 104056, 222338, 495358, 1064138, 2373070, 5119796, 11425974, 24738074, 55242788, 119958510, 268018844, 583462384, 1304179214, 2845288284, 6362293924

Offset: 1

Author

R. H. Hardin Nov 14 2011

Keywords

• nonn

Comments

Column 2 of A200192

Examples

			Some solutions for n=5
.-2....0...-2....0...-1....2....2...-2...-1...-1...-2....1....1....2...-1....0
..1....2....2...-2....2...-2...-2....2....2....1....2...-1...-2...-1....2....2
.-1...-2...-1....2...-1....2....0...-2...-1...-1....0....2....1....1...-2...-1
..2....1....2...-2....1...-2...-2....2....2....2....2...-2...-1...-2....2....1
..0...-1...-1....2...-1....0....2....0...-2...-1...-2....0....1....0...-1...-2
		

Links

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