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 A063681 Primes p such that 2p+7 is a power of three. 0
 37, 265717, 193710241, 1270932914161, 187855106306818130162790081799568953899918191769361, 884821727139988111281341588371104523273965529248966451172919369920848760385637 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS If (3^i-7)/2 is prime then x=3^i-7 is a solution of sigma(x)+7 = sigma(x+7). See A063680 and indices resulting in primes are in A063679. The next term (a(7)) has 118 digits. - Harvey P. Dale, May 10 2014 LINKS FORMULA 2*37+7 = 3^4, so 37 is in the sequence. MATHEMATICA Select[(#-7)/2&/@(3^Range[2, 250]), PrimeQ] (* Harvey P. Dale, May 10 2014 *) CROSSREFS Cf. A063679, A063680. Sequence in context: A262786 A140746 A262646 * A289820 A087020 A238840 Adjacent sequences:  A063678 A063679 A063680 * A063682 A063683 A063684 KEYWORD nonn AUTHOR Jud McCranie, Jul 29 2001 STATUS approved

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Last modified May 13 11:44 EDT 2021. Contains 343839 sequences. (Running on oeis4.)