

A092816


Number of Sophie Germain primes less than 10^n.


8



3, 10, 37, 190, 1171, 7746, 56032, 423140, 3308859, 26569515, 218116524, 1822848478, 15462601989, 132822315652
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OFFSET

1,1


COMMENTS

HardyLittlewood conjecture: Number of Sophie Germain primes less than n ~ 2*C2*n/(log(n))^2, where C2 = 0.6601618158... is the twin prime constant (see A005597). The truth of the above conjecture would imply that there are an infinite number of Sophie Germain primes (which is also conjectured).  Robert G. Wilson v, Jan 31 2013


REFERENCES

P. Ribenboim, The Little Book of Big Primes, SpringerVerlag, New York, 1991, p. 228.


LINKS

Table of n, a(n) for n=1..14.
C. K. Caldwell, An amazing prime heuristic, Table 6.
Eric Weisstein's World of Mathematics, Sophie Germain Prime


CROSSREFS

Cf. A005384, A156874, A182265.
Sequence in context: A250307 A289990 A123636 * A078109 A149045 A149046
Adjacent sequences: A092813 A092814 A092815 * A092817 A092818 A092819


KEYWORD

nonn


AUTHOR

Eric W. Weisstein, Mar 06 2004


EXTENSIONS

a(10) computed by Eric W. Weisstein, Nov 02 2005
a(11)a(12) from Donovan Johnson, Jun 19 2010
a(13)a(14) from Giovanni Resta, Sep 04 2017


STATUS

approved



