login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Numbers n such that n^8-8 is prime.
5

%I #13 Feb 20 2017 14:47:21

%S 3,7,19,39,73,75,101,107,145,147,171,213,235,247,263,285,319,353,359,

%T 369,399,443,445,521,523,557,613,675,693,707,733,781,791,805,815,829,

%U 837,879,927,943,961,999,1033,1097,1103,1109,1129,1137,1141,1155,1157

%N Numbers n such that n^8-8 is prime.

%C Note that all the numbers in this sequence are odd.

%e 3^8-8 = 6553 is prime. Thus, 3 is a member of this sequence.

%t Select[Range[3,1200,2],PrimeQ[#^8-8]&] (* _Harvey P. Dale_, Jun 27 2014 *)

%o (Python)

%o import sympy

%o from sympy import isprime

%o {print(n) for n in range(10**4) if isprime(n**8-8)}

%o (PARI) is(n)=isprime(n^8-8) \\ _Charles R Greathouse IV_, Feb 20 2017

%Y Cf. A028870, A153974, A239413, A239414, A239415, A239417, A239418, A239345.

%K nonn

%O 1,1

%A _Derek Orr_, Mar 17 2014