login
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