A199913 Number of -n..n arrays x(0..5) of 6 elements with zero sum, and adjacent elements not equal modulo three (with -1 modulo 3 = 2)

32, 232, 1312, 5016, 12872, 29864, 62776, 114768, 200520, 335216, 522160, 792880, 1174320, 1666712, 2327312, 3198184, 4271544, 5640984, 7367048, 9427264, 11963896, 15059328, 18668000, 22994912, 28147648, 34047432, 40977792, 49074872

Offset

1,1

Comments

Row 6 of A199909

Links

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

Formula

Empirical: a(n) = 2*a(n-1) -a(n-2) +4*a(n-3) -8*a(n-4) +4*a(n-5) -6*a(n-6) +12*a(n-7) -6*a(n-8) +4*a(n-9) -8*a(n-10) +4*a(n-11) -a(n-12) +2*a(n-13) -a(n-14)

Example

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

Crossrefs

Sequence in context: A022146 A160061 A269585 * A301795 A301968 A208641

Adjacent sequences: A199910 A199911 A199912 * A199914 A199915 A199916

Keyword

nonn

Author

R. H. Hardin Nov 11 2011

Status

approved