login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A063910 Primes p such that 2*p - 7 is also prime. 3

%I

%S 5,7,13,19,37,43,67,73,79,103,109,139,157,193,223,277,307,313,349,367,

%T 373,379,397,409,433,457,463,487,499,523,547,619,643,727,733,739,769,

%U 787,853,877,883,919,937,997,1009,1069,1093,1123,1129,1237

%N Primes p such that 2*p - 7 is also prime.

%C All terms > 5 are == 1 (mod 6). - _Zak Seidov_, Jan 07 2014

%H Harry J. Smith, <a href="/A063910/b063910.txt">Table of n, a(n) for n = 1..1000</a>

%F A089192 INTERSECT A000040. - _R. J. Mathar_, Mar 23 2017

%t Select[Prime[Range[2, 2000]], PrimeQ[2 # - 7]&] (* _Vincenzo Librandi_, Feb 02 2014 *)

%o (PARI) { n=0; p=1; for (m=1, 10^9, p=nextprime(p+1); if (isprime(2*p - 7), write("b063910.txt", n++, " ", p); if (n==1000, break)) ) } \\ _Harry J. Smith_, Sep 02 2009

%o (MAGMA) [n: n in [3..2000] | IsPrime(n) and IsPrime(2*n-7)]; // _Vincenzo Librandi_, Feb 02 2014

%K easy,nonn

%O 1,1

%A _N. J. A. Sloane_, Aug 31 2001

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 7 20:36 EDT 2021. Contains 343652 sequences. (Running on oeis4.)