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%I #13 Nov 12 2023 16:11:06
%S 53,701,59021,14348879,31381059581,282429536453,7625597484959,
%T 50031545098999679,1144561273430837494885949696399,
%U 26183890704263137277674192438430182020124319,2120895147045314119491609587512844743630072079
%N Primes of the form 3^k - 28.
%H Robert Price, <a href="/A289808/b289808.txt">Table of n, a(n) for n = 1..18</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^A219047(n) - 28. - _Elmo R. Oliveira_, Nov 12 2023
%t Select[Table[3^k - 28], {k, 4, 100}], PrimeQ[#] &]
%Y Cf. A000040, A219047 (corresponding k's).
%K nonn
%O 1,1
%A _Robert Price_, Sep 02 2017
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