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!)
A152388 Primes p such that (p-n)/(n+1) and (n+1)*p+n are both prime, with n=127. 1
6143, 11519, 23039, 205823, 253439, 345599, 417023, 463103, 752639, 1071359, 1474559, 1511423, 1753343, 1766399, 1903103, 2188799, 2271743, 2711039, 2741759, 2747903, 2813183, 2997503, 3032063, 3258623, 3371519, 3463679 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
This is the general form : (p-n)/(n+1)=primeand(n+1)*p+n=prime; 'Safe' primes and'Sophie Germain' primes just one part of this general form; If n=1 then we got'Safe' primes and'Sophie Germain' primes.
LINKS
MATHEMATICA
lst={}; n=127; Do[p=Prime[k]; If[PrimeQ[(p-n)/(n+1)]&&PrimeQ[(n+1)*p+n], AppendTo[lst, p]], {k, 2*9!}]; lst
Select[Prime[Range[250000]], AllTrue[{(#-127)/128, 128#+127}, PrimeQ]&] (* Harvey P. Dale, Apr 30 2023 *)
CROSSREFS
Sequence in context: A144491 A184501 A205833 * A251787 A203982 A204626
KEYWORD
nonn
AUTHOR
EXTENSIONS
Definition clarified by Harvey P. Dale, Apr 30 2023
STATUS
approved

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 24 20:08 EDT 2024. Contains 371963 sequences. (Running on oeis4.)