A069460 Greatest prime factor of prime(n)^n - 1.

2, 31, 5, 3221, 157, 25646167, 3833, 7792003, 732541, 150332843, 144061, 17615988547, 6177695707, 461017351, 31129845205681, 361353204962363828785531, 903870199, 751410597400064602523400427092397, 25058741, 153436090543, 1750258119644519

Offset

2,1

Links

Hugo Pfoertner and Amiram Eldar, Table of n, a(n) for n = 2..96 (terms 2..50 from Hugo Pfoertner)

Dario Alpern, Factorization using the Elliptic Curve Method.

FactorDB, Status of 509^97-1.

Formula

a(n) = A006530(A069459(n)).

Example

A000040(9)^9 - 1 = 23^9 - 1 = 1801152661462 = 2*7*11*19*79*7792003, therefore a(9) = 7792003.

Mathematica

Table[FactorInteger[Prime[n]^n-1][[-1, 1]], {n, 2, 30}] (* Harvey P. Dale, May 19 2019 *)

Crossrefs

Cf. A006530, A069459, A069463.

Sequence in context: A159578 A221192 A178194 * A352959 A117816 A237263

Adjacent sequences: A069457 A069458 A069459 * A069461 A069462 A069463

Keyword

nonn

Author

Reinhard Zumkeller, Mar 24 2002

Extensions

More terms from Hugo Pfoertner, May 18 2004

Undefined a(1) removed by Hugo Pfoertner, Jul 22 2019

Status

approved