A284785 a(n) = rad(A280864(n)).

1, 2, 2, 3, 6, 2, 5, 10, 6, 3, 7, 14, 2, 11, 22, 6, 15, 10, 6, 21, 14, 26, 13, 17, 34, 30, 15, 19, 38, 2, 23, 46, 6, 3, 5, 35, 42, 6, 29, 58, 10, 55, 33, 39, 26, 22, 77, 7, 31, 62, 10, 65, 78, 6, 37, 74, 14, 21, 51, 34, 30, 15, 41, 82, 2, 43, 86

Offset

1,2

Comments

By definition, all terms are squarefree (see A007947); repeated terms here are the squarefree kernels of A280864(n).

All even squarefree numbers appear infinitely often.

1 appears only at a(1).

Even terms appear consecutively in pairs, each pair followed by one or more odd terms.

Conjecture: all odd squarefree numbers > 1 appear infinitely often. If so, then A280864 is a permutation of the natural numbers.

Theorem: a(n) = b(n-1)*b(n) where b = A280738. - N. J. A. Sloane, Apr 11 2017

Links

Table of n, a(n) for n=1..67.

Example

a(61) = 30 because A280864(61) = 60, and rad(60) = 30.

Crossrefs

Cf. A280864, A284311, A284457, A007947, A280738.

Sequence in context: A210222 A207621 A209157 * A076333 A015051 A362199

Adjacent sequences: A284782 A284783 A284784 * A284786 A284787 A284788

Keyword

nonn

Author

Bob Selcoe, Apr 02 2017

Status

approved