

A000355


Primes = 3, 9, 11 (mod 20) such that 2p+1 is also prime.


3



3, 11, 23, 29, 83, 89, 131, 191, 251, 431, 443, 491, 509, 683, 743, 809, 911, 1031, 1049, 1103, 1223, 1229, 1289, 1409, 1451, 1511, 1583, 1811, 1889, 1931, 2003, 2063, 2069, 2129, 2351, 2543, 2549, 2903, 2963, 2969, 3023, 3329, 3389, 3449, 3491, 3623, 3803
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OFFSET

1,1


COMMENTS

a(n) = (A000353(n)1)/2; [From Reinhard Zumkeller, Feb 10 2009]


REFERENCES

R. A. J. Matthews, Maximally periodic reciprocals, Bull. Institute of Mathematics and Its Applications, vol. 28, p. 147148, 1992.


LINKS

R. Zumkeller, Table of n, a(n) for n = 1..1000 [From Reinhard Zumkeller, Feb 10 2009]


CROSSREFS

Subset of A005384.
Sequence in context: A177789 A141226 A049491 * A163769 A100860 A018630
Adjacent sequences: A000352 A000353 A000354 * A000356 A000357 A000358


KEYWORD

nonn,easy


AUTHOR

R. A. J. Matthews [ 100265.3005(AT)compuserve.com ]


EXTENSIONS

More terms from Reinhard Zumkeller, Feb 10 2009


STATUS

approved



