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A016027 Indices of prime Mersenne numbers (A001348). 4
1, 2, 3, 4, 6, 7, 8, 11, 18, 24, 28, 31, 98, 111, 207, 328, 339, 455, 583, 602, 1196, 1226, 1357, 2254, 2435, 2591, 4624, 8384, 10489, 12331, 19292, 60745, 68301, 97017, 106991, 215208, 218239, 474908, 877615, 1329726 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

The following are also members of the sequence: 1329726, 1509263, 1622441, 1881339, 2007537, 2270720, 2584328, and 2610944.

REFERENCES

Paulo Ribenboim, "Galimatias arithmeticae", Mathematics Magazine, vol. 71, no. 5, page 337, Dec. 1998.

R. K. Guy, Unsolved Problems in Number Theory, 3rd ed., Springer-Verlag, NY, 2004, Sec. A3.

G. H. Hardy and E. M. Wright, An Introduction to the Theory of Numbers, 3rd ed., Oxford Univ. Press, 1954, p. 16.

P. Ribenboim, The New Book of Prime Number Records, Springer-Verlag, NY, 1996, Chap. 2, Sec. VII.

LINKS

C. K. Caldwell, Mersenne Primes

Will Edgington, List of Mersenne primes

Great Internet Mersenne Prime Search (GIMPS), Distributed Computing Projects

Andrew R. Booker, The Nth Prime Page

FORMULA

Pi(A000043).

EXAMPLE

The first four Mersenne numbers 2^2 - 1 = 3, 2^3 - 1 = 7, 2^5 - 1 = 31 and 2^7 - 1 = 127 are prime, so 1, 2, 3, 4 are members. But the fifth Mersenne number 2^11 - 1 = 2047 = 23*89 is composite, so 5 is not a member.

MATHEMATICA

a = {}; Do[If[PrimeQ[2^Prime[n] - 1], AppendTo[a, n]], {n, 1, 100}]; a (*Artur Jasinski*)

CROSSREFS

Cf. A000043, A001348.

See also A059305 Pi(n-th Mersenne prime).

Sequence in context: A163866 A027206 A198034 * A205591 A191282 A191281

Adjacent sequences:  A016024 A016025 A016026 * A016028 A016029 A016030

KEYWORD

nonn,nice,hard

AUTHOR

Robert G. Wilson v (rgwv(AT)rgwv.com)

EXTENSIONS

Corrected by Vasiliy Danilov (danilovv(AT)usa.net) Jun 15 1998. Further corrections from Reto Keiser (rkeiser(AT)stud.ee.ethz.ch), Jan 10, 2001.

a(39) from Robert G. Wilson v (rgwv(at)rgwv.com), Mar 20 2006.

a(40) from Robert G. Wilson v (rgwv(at)rgwv.com), May 29 2011.

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Last modified February 17 21:13 EST 2012. Contains 206085 sequences.