A215398 Number of length n 0..5 arrays connected end-around, with no sequence of L<n elements immediately followed by itself (periodic "squarefree"), and new values introduced in order 0..5.

1, 1, 1, 3, 6, 27, 98, 442, 1968, 9214, 43263, 205749, 979979, 4684197, 22406501, 107279908, 513768237, 2461123503, 11790546197

Offset

1,4

Comments

Column 5 of A215401.

Links

Table of n, a(n) for n=1..19.

Example

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

Crossrefs

Sequence in context: A217725 A023169 A083695 * A215399 A215400 A215394

Adjacent sequences: A215395 A215396 A215397 * A215399 A215400 A215401

Keyword

nonn

Author

R. H. Hardin, Aug 09 2012

Status

approved