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!)
A053705 Primes p of form q^k-2 where q is also a prime and k > 1. 3
2, 7, 23, 47, 79, 167, 241, 359, 727, 839, 1367, 1847, 2207, 2399, 3719, 5039, 6857, 7919, 10607, 11447, 14639, 16127, 17159, 19319, 19681, 28559, 29789, 29927, 36479, 44519, 49727, 50651, 54287, 57119, 66047, 85847, 97967, 113567, 128879 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

79=3^4-2, 243=3^5-2.

LINKS

Table of n, a(n) for n=1..39.

MATHEMATICA

Do[s=2+Prime[n]; If[Equal[Length[FactorInteger[s]], 1]&&!PrimeQ[s], Print[s-2]], {n, 1, 100000}]

fQ[n_] := PrimeNu[n + 2] == 1 && ! PrimeQ[n + 2]; Select[ Prime@ Range@ 15000, fQ] (* Robert G. Wilson v, Apr 01 2012 *)

PROG

(PARI) lista(nn) = forprime (p=1, nn, if (ispower(p+2, , &q) && isprime(q), print1(p, ", ")); ); \\ Michel Marcus, Dec 11 2014

CROSSREFS

Cf. A025475. Subsequence of A053705.

Sequence in context: A049572 A094786 A028871 * A247175 A049001 A049002

Adjacent sequences:  A053702 A053703 A053704 * A053706 A053707 A053708

KEYWORD

nonn

AUTHOR

Labos Elemer, Feb 14 2000

EXTENSIONS

Definition corrected by Zak Seidov, Dec 11 2014

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 3 21:19 EDT 2021. Contains 346441 sequences. (Running on oeis4.)