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!)
A100742 Smallest prime p such that (p+prime(n))/2 is prime. 1

%I

%S 2,3,5,3,3,13,5,3,3,5,3,37,5,3,11,5,3,13,7,3,13,3,3,5,37,5,3,11,13,5,

%T 7,3,5,3,17,7,37,3,11,5,23,13,3,13,5,3,3,3,47,73,29,23,13,3,5,11,5,3,

%U 37,17,19,5,7,3,13,17,3,61,11,13,5,3,19,13,3,3,5,61,53,13,3,37,23,13,7,3,5

%N Smallest prime p such that (p+prime(n))/2 is prime.

%o (PARI) a(n) = {if (n==1, return (2)); p = 3; while(! isprime((prime(n)+p)/2), p = nextprime(p+1)); return (p);} \\ _Michel Marcus_, Jun 16 2013

%Y Cf. A084704.

%K easy,nonn,less

%O 1,1

%A _David Wasserman_, Jan 03 2005

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 13 23:41 EDT 2021. Contains 343868 sequences. (Running on oeis4.)