A200196 Number of -n..n arrays x(0..6) of 7 elements with zero sum, adjacent elements differing by more than one, and elements alternately increasing and decreasing.

0, 104, 1534, 9856, 40632, 127800, 334278, 765598, 1585416, 3034396, 5450616, 9293800, 15170448, 23863548, 36362438, 53897896, 77976766, 110422568, 153414642, 209534448, 281809258, 373763982, 489469484, 633600106, 811486280

Offset: 1

Author

R. H. Hardin Nov 14 2011

Keywords

• nonn

Comments

Row 7 of A200192

Examples

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

Links

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

Formula

Empirical: a(n) = 2*a(n-1) -a(n-3) -a(n-5) +a(n-6) -2*a(n-7) +2*a(n-8) +a(n-9) -a(n-13) -2*a(n-14) +2*a(n-15) -a(n-16) +a(n-17) +a(n-19) -2*a(n-21) +a(n-22)