A199828 Number of -4..4 arrays x(0..n+1) of n+2 elements with zero sum and no two neighbors summing to zero.

44, 336, 2146, 15708, 118280, 888420, 6715618, 51077518, 390278378, 2993722414, 23038998514, 177794832922, 1375379617514, 10662124449466, 82808224932874, 644200988262616, 5018935818153796, 39154328577073846, 305823285072243150

Offset: 1

Author

R. H. Hardin Nov 11 2011

Keywords

• nonn

Comments

Column 4 of A199832

Examples

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

Links

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