login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A175173 Primes p such that 2^p+5 is also prime. 1
3, 5, 11, 47, 53, 191, 34763 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(8) > 5*10^5. - Robert Price, Sep 18 2015

LINKS

Table of n, a(n) for n=1..7.

FORMULA

A000040 INTERSECT A059242. [R. J. Mathar, May 02 2010]

EXAMPLE

For p=3, 2^3+5=13; p=5, 2^5+5=37; p=11, 2^11+5=2053

MATHEMATICA

Select[Prime@ Range@ 1000, PrimeQ[2^# + 5] &] (* Michael De Vlieger, Sep 18 2015 *)

PROG

(Magma) [p: p in PrimesUpTo(7000) | IsPrime(2^p+5) ]

CROSSREFS

Sequence in context: A144467 A049883 A059242 * A268510 A004203 A201473

Adjacent sequences: A175170 A175171 A175172 * A175174 A175175 A175176

KEYWORD

nonn

AUTHOR

Vincenzo Librandi, Mar 09 2010

EXTENSIONS

a(7) from Robert Price, Sep 18 2015

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 30 04:37 EST 2022. Contains 358431 sequences. (Running on oeis4.)