A088038 Smallest cube k == 1 (mod some n-th power), k > 1.

8, 64, 729, 4913, 35937, 274625, 2146689, 16974593, 135005697, 1076890625, 8602523649, 68769820673, 549957165057, 4398851866625, 35187593412609, 281487861809153, 2251851353686017, 18014604668698625, 144116012711149569

Offset

1,1

Comments

In most of the cases the n-th power that divides a(n)-1 is 2^n.

Links

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

Formula

Empirical G.f.: -x*(3904*x^5-6104*x^4+2502*x^3-329*x^2+56*x-8) / ((x-1)*(2*x-1)*(4*x-1)*(8*x-1)). [Colin Barker, Feb 05 2013]

Example

a(4) = 4913 = 17^3 and 4912 = (2^4)*307.

Crossrefs

Cf. A088039.

Sequence in context: A204212 A238724 A318640 * A061435 A133054 A371988

Adjacent sequences: A088035 A088036 A088037 * A088039 A088040 A088041

Keyword

nonn

Author

Amarnath Murthy, Sep 19 2003

Extensions

More terms from Ray Chandler, Oct 04 2003

Status

approved