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”).

Primes of the form 3^k - 16.
1

%I #28 Nov 12 2023 08:27:10

%S 11,227,177131,14348891,2153693963075557766310731,

%T 834385168331080533771857328695267,

%U 171792506910670443678820376588540424234035840651,2025465365549235636389379590279612045176776005882811610332067323733925450296747107485272801773488928849912971

%N Primes of the form 3^k - 16.

%H Robert Price, <a href="/A289716/b289716.txt">Table of n, a(n) for n = 1..9</a>

%H F. Firoozbakht and M. F. Hasler, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL13/Hasler/hasler2.html">Variations on Euclid's formula for Perfect Numbers</a>, JIS 13 (2010) #10.3.1.

%H Henri and Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop">PRP Records</a>

%H OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">Primality Tester</a>

%F a(n) = 3^A219039(n) - 16. - _Elmo R. Oliveira_, Nov 12 2023

%t Select[Table[3^k - 16], {k, 3, 100}], PrimeQ[#] &]

%Y Cf. A000040, A219039 (corresponding k's).

%K nonn

%O 1,1

%A _Robert Price_, Sep 02 2017