

A057177


Numbers n such that (11^n + 1)/12 is a prime.


13




OFFSET

1,1


LINKS

Table of n, a(n) for n=1..9.
Paul Bourdelais, A Generalized Repunit Conjecture
J. Brillhart et al., Factorizations of b^n + 1, Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 3rd edition, 2002.
H. Dubner and T. Granlund, Primes of the Form (b^n+1)/(b+1), J. Integer Sequences, 3 (2000), #P00.2.7.
H. Lifchitz, Mersenne and Fermat primes field
Eric Weisstein's World of Mathematics, Repunit


MATHEMATICA

lst={}; Do[p=(11^n+1)/12; If[PrimeQ[p], AppendTo[lst, n]], {n, 7!}]; lst (* Vladimir Joseph Stephan Orlovsky, Sep 29 2008 *)


CROSSREFS

Sequence in context: A164372 A318088 A123536 * A297535 A211769 A265031
Adjacent sequences: A057174 A057175 A057176 * A057178 A057179 A057180


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, Sep 15 2000


EXTENSIONS

a(8) corresponds to a probable prime discovered by Paul Bourdelais, Feb 12 2010
a(9) corresponds to a probable prime discovered by Paul Bourdelais, Sep 30 2013


STATUS

approved



