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!)
A107438 Primes p such that 7*p+2 or 2*p+7 is prime. 1
2, 3, 5, 11, 17, 23, 41, 47, 53, 71, 83, 101, 107, 113, 131, 137, 167, 173, 191, 197, 227, 251, 257, 281, 293, 311, 317, 347, 353, 383, 401, 431, 461, 467, 503, 521, 563, 587, 593, 641, 647, 677, 683, 701, 743, 773, 797, 821, 827, 857, 863, 887, 911, 941, 947 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..55.

MATHEMATICA

Select[Prime[Range[220]], PrimeQ[2#+7]||PrimeQ[7#+2]&] (* Shepherd *)

PROG

(PARI) isok(n) = isprime(n) && (isprime(7*n+2) || isprime(2*n+7)); \\ Michel Marcus, Oct 06 2013

CROSSREFS

Cf. A105760 Numbers n such that (2*n + 7) is prime; A105772 Numbers n such that (7*n + 2) is prime.

Sequence in context: A049553 A049595 A258039 * A211204 A023206 A049565

Adjacent sequences:  A107435 A107436 A107437 * A107439 A107440 A107441

KEYWORD

nonn

AUTHOR

Zak Seidov, May 26 2005

EXTENSIONS

Edited by Rick L. Shepherd, Feb 01 2006

STATUS

approved

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 August 5 06:46 EDT 2020. Contains 336209 sequences. (Running on oeis4.)