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A006033 Numbers n such that (15^n - 1)/14 is prime.
(Formerly M3150)
13
3, 43, 73, 487, 2579, 8741, 37441, 89009, 505117, 639833 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
8741 and 37441 are only probable primes. - Julien Peter Benney (jpbenney(AT)ftml.net), Apr 27 2007
REFERENCES
Paulo Ribenboim, "The Book Of Prime Number Records"; published 1989 by Springer-Verlag; pages 350-354.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Harvey Dubner, Generalized repunit primes, Math. Comp., 61 (1993), 927-930.
H. Dubner, Generalized repunit primes, Math. Comp., 61 (1993), 927-930. [Annotated scanned copy]
EXAMPLE
(15^3 - 1)/14 = 241, which is prime.
MATHEMATICA
lst={}; Do[If[PrimeQ[(15^n-1)/14], Print[n]; AppendTo[lst, n]], {n, 10^5}]; lst (* Vladimir Joseph Stephan Orlovsky, Aug 21 2008 *)
PROG
(PARI) is(n)=ispseudoprime((15^n-1)/14) \\ Charles R Greathouse IV, Apr 29 2015
CROSSREFS
Sequence in context: A139854 A194578 A185632 * A246994 A142184 A199348
KEYWORD
nonn,hard,more
AUTHOR
EXTENSIONS
a(7) from Julien Peter Benney (jpbenney(AT)ftml.net), Apr 27 2007
a(8) corresponds to a probable prime discovered by Paul Bourdelais, Mar 15 2010
a(9) corresponds to a probable prime discovered by Paul Bourdelais, Jan 14 2015
a(10) corresponds to a probable prime discovered by Paul Bourdelais, Apr 22 2019
STATUS
approved

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Last modified June 30 01:43 EDT 2024. Contains 373859 sequences. (Running on oeis4.)