A215225 Number of length-n 0..5 arrays connected end-around, with no sequence of L<n elements immediately followed by itself (periodic "squarefree").

6, 30, 120, 600, 2520, 12600, 57960, 280560, 1330560, 6394680, 30548760, 146516040, 701454000, 3361690080, 16104243120

Offset

1,1

Comments

Column 5 of A215228.

Links

Table of n, a(n) for n=1..15.

Example

Some solutions for n=8:
..3....0....1....3....0....0....3....3....0....3....3....3....0....0....4....0
..2....2....5....4....1....4....4....2....4....1....2....4....3....2....0....2
..1....1....4....2....0....5....0....0....0....4....5....1....1....3....4....5
..2....0....3....1....3....1....3....5....1....0....4....5....0....2....3....2
..0....3....5....5....4....3....1....2....5....3....0....0....4....4....5....0
..5....4....0....3....0....4....5....4....4....1....3....1....5....3....0....5
..2....2....3....1....4....5....2....2....1....2....1....0....0....2....2....1
..5....4....4....0....3....1....1....0....5....5....5....5....4....5....1....5

Crossrefs

Sequence in context: A346174 A182349 A371036 * A056385 A266945 A369819

Adjacent sequences: A215222 A215223 A215224 * A215226 A215227 A215228

Keyword

nonn,more

Author

R. H. Hardin, Aug 06 2012

Status

approved