A075081 Perfect powers q (A001597) such that (q-1)/2 is prime.

27, 2187, 1594323, 7509466514979724803946715958257547, 13915193059764305937984450503671774362956903094027

Offset

1,1

Comments

It can be shown that q must be of the form 3^e with e prime.

The next terms are 3^541, 3^1091, 3^1367, 3^1627, 3^4177, 3^9011, 3^9551, ...

Links

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

Crossrefs

Cf. A075079, A076481, A028491.

Sequence in context: A017199 A223476 A013779 * A017307 A167725 A366181

Adjacent sequences: A075078 A075079 A075080 * A075082 A075083 A075084

Keyword

nonn,hard

Author

Zak Seidov, Oct 16 2002

Extensions

Extended by Dean Hickerson, Oct 16 2002

Status

approved