A215226 Number of length-n 0..6 arrays connected end-around, with no sequence of L<n elements immediately followed by itself (periodic "squarefree").

7, 42, 210, 1260, 6720, 40110, 228480, 1338120, 7761600, 45291120, 263674950, 1537291560

Offset

1,1

Comments

Column 6 of A215228.

Links

Table of n, a(n) for n=1..12.

Example

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

Crossrefs

Sequence in context: A319890 A319871 A261482 * A349427 A200864 A279613

Adjacent sequences: A215223 A215224 A215225 * A215227 A215228 A215229

Keyword

nonn,more

Author

R. H. Hardin, Aug 06 2012

Status

approved