A200453 Number of -7..7 arrays x(0..n+1) of n+2 elements with zero sum and nonzero first and second differences.

142, 1832, 22276, 278906, 3513884, 44716536, 572857272, 7380022092, 95496980144, 1240352594210, 16161267003100, 211148128583658, 2765181621011902, 36287540439791446, 477071904597059874, 6282247056373911518

Offset: 1

Author

R. H. Hardin Nov 18 2011

Keywords

• nonn

Comments

Column 7 of A200454.

Examples

			Some solutions for n=3
.-1...-4....0....7....5....5....6...-4....2....0...-1...-5....4....2...-6...-6
.-3....3....2....0...-1....2...-2....6....3....4....2....6...-5....3...-1....7
..4....4...-5...-1...-2...-6...-4....4...-5...-1...-3....1....1...-4....1...-6
.-5...-3....3...-4...-4...-4...-7....0...-1...-4....4...-5...-3....3....6....2
..5....0....0...-2....2....3....7...-6....1....1...-2....3....3...-4....0....3
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..97