A200448 Number of -2..2 arrays x(0..n+1) of n+2 elements with zero sum and nonzero first and second differences.

10, 44, 144, 486, 1582, 5478, 18692, 64782, 223272, 776430, 2701660, 9439702, 33021250, 115801892, 406698282, 1430840312, 5040451088, 17779563894, 62784860258, 221948186878, 785340477204, 2781302241584, 9857972484436

Offset: 1

Author

R. H. Hardin Nov 18 2011

Keywords

• nonn

Comments

Column 2 of A200454

Examples

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

Links

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