|
Search: id:A057172
|
|
|
| A057172 |
|
Numbers n such that (6^n + 1)/7 is a prime. |
|
+0
2
|
|
| 3, 11, 31, 43, 47, 59, 107, 811, 2819, 4817, 9601, 33581, 38447, 41341
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
LINKS
|
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.
Eric Weisstein's World of Mathematics, Repunit
H. Lifchitz, Mersenne and Fermat primes field
|
|
MATHEMATICA
|
lst={}; Do[p=(6^n+1)/7; If[PrimeQ[p], AppendTo[lst, n]], {n, 7!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Sep 29 2008]
|
|
CROSSREFS
|
Adjacent sequences: A057169 A057170 A057171 this_sequence A057173 A057174 A057175
Sequence in context: A003523 A018781 A119215 this_sequence A071568 A093406 A097081
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
njas, Sep 15 2000
|
|
EXTENSIONS
|
a(12) was discovered by Kamil Duszenko, Jul 15 2003; a(13) was discovered by Henri Lifchitz Sep 15 2007; a(14) was discovered by Paul Bourdelais, Oct 01 2007.
|
|
|
Search completed in 0.002 seconds
|
