A199906 Number of -5..5 arrays x(0..n-1) of n elements with zero sum, and adjacent elements not equal modulo three (with -1 modulo 3 = 2)

1, 8, 60, 256, 1836, 12872, 77874, 547604, 3784512, 25525476, 179010266, 1249682864, 8709865930, 61360521500, 432263649142, 3049721406636, 21595190691722, 153069769124720, 1086568858888600, 7726348605601340

Offset

1,2

Comments

Column 5 of A199909

Links

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

Example

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

Crossrefs

Sequence in context: A032365 A250315 A074423 * A297690 A268599 A250556

Adjacent sequences: A199903 A199904 A199905 * A199907 A199908 A199909

Keyword

nonn

Author

R. H. Hardin Nov 11 2011

Status

approved