The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
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!)
A143912 Primes of the form : 2*p+1=p1(prime), 2*p1+3=p2(prime), 2*p2+5=p3(prime). 1

%I #6 Nov 21 2013 12:49:25

%S 2,23,113,191,233,443,593,1031,1409,2129,2399,2543,4349,4481,4919,

%T 5231,5399,6263,6329,6449,7541,10253,10613,11321,12101,13463,13553,

%U 13763,14009,15773,15923,17333,17939,18233,18341,18461,18803,19559,19661

%N Primes of the form : 2*p+1=p1(prime), 2*p1+3=p2(prime), 2*p2+5=p3(prime).

%C Subset of A005384. [From _R. J. Mathar_, Sep 05 2008]

%H Harvey P. Dale, <a href="/A143912/b143912.txt">Table of n, a(n) for n = 2..1000</a>

%e (prime)2*2+1=5(prime), 2*5+3=13(prime), 2*13+5=31(prime).

%t lst={};Do[p=Prime[n];If[PrimeQ[p1=2*p+1]&&PrimeQ[p2=2*p1+3]&&PrimeQ[p3=2*p2+5],AppendTo[lst,p]],{n,10^4}];lst

%t pfQ[n_]:=Module[{p1=2n+1,p2},p2=2p1+3;And@@PrimeQ[{p1,p2,2p2+5}]]; Select[Prime[ Range[2300]],pfQ] (* _Harvey P. Dale_, Nov 03 2011 *)

%K nonn

%O 2,1

%A _Vladimir Joseph Stephan Orlovsky_, Sep 04 2008

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 May 16 16:26 EDT 2024. Contains 372554 sequences. (Running on oeis4.)