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

1,2

Comments

Row 7 of A200192

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)

Example

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

Crossrefs

Sequence in context: A340898 A132434 A187589 * A234219 A223420 A250325

Adjacent sequences: A200193 A200194 A200195 * A200197 A200198 A200199

Keyword

nonn

Author

R. H. Hardin Nov 14 2011

Status

approved