A215394 Number of length-n 0..n arrays connected end-around, with no sequence of L<n elements immediately followed by itself (periodic "squarefree"), and new values introduced in order 0..n.

1, 1, 1, 3, 6, 27, 99, 463, 2233, 11875, 66925, 402364, 2555606, 17115329, 120368115, 886510373, 6819231506

Offset

1,4

Comments

Diagonal of A215401.

Links

Table of n, a(n) for n=1..17.

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....0....0....2....2....2....2....2....0....2....2....0....2
..0....3....3....0....2....2....3....3....0....3....1....2....0....3....2....0
..2....2....1....3....0....3....4....0....3....0....0....3....3....1....1....1
..1....4....4....4....3....2....1....2....2....4....3....4....1....2....3....3

Crossrefs

Sequence in context: A215398 A215399 A215400 * A222625 A060170 A223143

Adjacent sequences: A215391 A215392 A215393 * A215395 A215396 A215397

Keyword

nonn,more

Author

R. H. Hardin, Aug 09 2012

Status

approved