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A175172 Primes p such that 3*2^p+1 is also prime. 0
2, 5, 41, 353 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..4.

FORMULA

A000040 INTERSECT A002253. - R. J. Mathar, Jan 04 2011

EXAMPLE

For p=2, 3*2^2+1=13; p=5. 3*2^5+1=97; p=41, 3*2^41+1=6597069766657

PROG

(MAGMA) [p: p in PrimesUpTo(4000) | IsPrime(3*2^p+1) ]

CROSSREFS

Sequence in context: A185052 A088547 A009457 * A218057 A126469 A054859

Adjacent sequences:  A175169 A175170 A175171 * A175173 A175174 A175175

KEYWORD

nonn

AUTHOR

Vincenzo Librandi, Mar 09 2010

STATUS

approved

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Last modified March 29 07:21 EDT 2017. Contains 284250 sequences.