

A006032


Numbers n such that (14^n  1)/13 is prime.
(Formerly M2670)


12




OFFSET

1,1


REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).


LINKS

Table of n, a(n) for n=1..10.
Paul Bourdelais, A Generalized Repunit Conjecture
H. Dubner, Generalized repunit primes, Math. Comp., 61 (1993), 927930.
H. Dubner, Generalized repunit primes, Math. Comp., 61 (1993), 927930. [Annotated scanned copy]
H. Lifchitz, Mersenne and Fermat primes field


MATHEMATICA

lst={}; Do[If[PrimeQ[(14^n1)/13], Print[n]; AppendTo[lst, n]], {n, 10^5}]; lst (* Vladimir Joseph Stephan Orlovsky, Aug 21 2008 *)


PROG

(PARI) is(n)=isprime((14^n  1)/13) \\ Charles R Greathouse IV, Apr 29 2015


CROSSREFS

Sequence in context: A056725 A091738 A136054 * A240072 A066148 A093932
Adjacent sequences: A006029 A006030 A006031 * A006033 A006034 A006035


KEYWORD

hard,nonn,more


AUTHOR

N. J. A. Sloane.


EXTENSIONS

One more term from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 05 2008
a(8) and a(9) correspond to probable primes discovered by Paul Bourdelais, Mar 01 2010
a(10) corresponds to a probable prime discovered by Paul Bourdelais, Dec 08 2014


STATUS

approved



