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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A129119 Numbers of the form 2*p (with p a prime number) such that p^2+4 is prime. 0

%I #9 Sep 27 2019 12:26:34

%S 6,10,14,26,34,74,94,134,146,194,206,274,326,334,386,466,554,586,614,

%T 626,634,694,746,926,974,1006,1094,1154,1186,1214,1226,1354,1486,1574,

%U 1646,1654,1706,1766,1906,1934,1966,1994,2174,2234,2246,2474,2734,2846

%N Numbers of the form 2*p (with p a prime number) such that p^2+4 is prime.

%F a(n) = 2*A062324(n).

%e 7^2 + 4 = 53 which is a prime number. Therefore 2*7 is in the sequence.

%t 2*Select[Prime@Range[250], PrimeQ[ #^2 + 4] &] (* _Ray Chandler_, May 27 2007 *)

%t a={};For[n=1,n<300,n++,If[PrimeQ[Prime[n]^2 + 4], AppendTo[a, 2*Prime[n]]]]; a (* _Stefan Steinerberger_, May 27 2007 *)

%Y Cf. A045637, A062324.

%K easy,nonn

%O 1,1

%A _Giovanni Teofilatto_, May 25 2007

%E Extended and edited by _Ray Chandler_ and _Stefan Steinerberger_, May 27 2007

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 April 23 20:33 EDT 2024. Contains 371916 sequences. (Running on oeis4.)