A215227 Number of length-n 0..7 arrays connected end-around, with no sequence of L<n elements immediately followed by itself (periodic "squarefree").

8, 56, 336, 2352, 15120, 105168, 710640, 4883424, 33384960, 228945360, 1568401296, 10751253072, 73683206688, 505043014560

Offset

1,1

Comments

Column 7 of A215228.

Links

Table of n, a(n) for n=1..14.

Example

Some solutions for n=5:
..7....2....0....6....7....7....6....7....3....7....6....0....1....2....5....0
..6....4....5....5....0....5....7....3....1....1....1....1....0....5....6....4
..1....3....6....7....6....7....5....7....5....5....5....2....7....1....3....1
..5....5....2....3....0....1....6....0....0....3....1....6....5....4....5....6
..0....6....1....5....4....4....1....6....4....4....7....7....0....0....7....4

Crossrefs

Sequence in context: A264946 A319891 A319872 * A034006 A334333 A307813

Adjacent sequences: A215224 A215225 A215226 * A215228 A215229 A215230

Keyword

nonn,more

Author

R. H. Hardin, Aug 06 2012

Status

approved