A200546 Number of -1..1 arrays x(0..n+1) of n+2 elements with zero sum and nonzero second differences.

4, 14, 26, 72, 142, 362, 778, 1938, 4366, 10628, 24532, 59138, 138680, 333014, 788374, 1890870, 4503208, 10803262, 25831504, 62025512, 148725902, 357516682, 859055042, 2067463940, 4975921904, 11988835382, 28892947100, 69685951942

Offset: 1

Author

R. H. Hardin Nov 19 2011

Keywords

• nonn

Comments

Column 1 of A200553

Examples

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

Links

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