A096059 Numbers n such that for all k, (n^k-1)/(n-1) is not prime.

9, 25, 32, 49, 64, 81, 121, 125, 144

Offset

1,1

Comments

Indices of 0 in A084740.

Possibly a subset of A001597.

The first unknown value is n=152, checked up to k = prime(1100). - Derek Orr, Nov 29 2014

It is known 169, 216, 225, 243, 289, 324, 343 are also members of this sequence. - Derek Orr, Nov 29 2014

Links

Table of n, a(n) for n=1..9.

Crossrefs

Cf. A001597, A084738, A084740.

Sequence in context: A270337 A339842 A068529 * A326742 A246328 A065772

Adjacent sequences: A096056 A096057 A096058 * A096060 A096061 A096062

Keyword

nonn,more

Author

Amarnath Murthy, Jun 17 2004

Extensions

Edited by Don Reble, Mar 19 2007

Status

approved