A088553 Primes of the form (3^k-1)/2 or (3^k+1)/2.

2, 5, 13, 41, 1093, 797161, 21523361, 926510094425921, 1716841910146256242328924544641, 3754733257489862401973357979128773, 6957596529882152968992225251835887181478451547013

Offset: 1

Author

Cino Hilliard, Nov 17 2003

Keywords

• nonn

Comments

The next term is too large to include.

The next term has 258 digits. - Harvey P. Dale, Dec 04 2018

Links

• Amiram Eldar, Table of n, a(n) for n = 1..15

Crossrefs

Cf. A028491, A096723, A171381.

Programs

Mathematica

Select[Flatten[Table[(3^x+{1,-1})/2,{x,150}]],PrimeQ] (* Harvey P. Dale, Dec 04 2018 *)

Extensions

Edited by Don Reble, May 03 2006