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A172996 Primes of form (3^n+7)/2. 2
5, 17, 1097, 304133393856678854559841996309430657 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..7

FORMULA

a(n) = (3^A172995(n)+7)/2.

MATHEMATICA

Select[Table[(3^n + 7)/2, {n, 500}], PrimeQ] (* Vincenzo Librandi, Sep 24 2015 *)

PROG

(MAGMA) [a: n in [0..500] | IsPrime(a) where a is (3^n+7) div 2]; // Vincenzo Librandi, Sep 24 2015

(PARI) for(n=1, 1e3, if(isprime(k=(3^n+7)/2), print1(k", "))) \\  Altug Alkan Sep 24 2015

CROSSREFS

Cf. A172995.

Sequence in context: A218378 A119531 A248921 * A253624 A085832 A062223

Adjacent sequences:  A172993 A172994 A172995 * A172997 A172998 A172999

KEYWORD

nonn

AUTHOR

Vincenzo Librandi, Feb 07 2010

STATUS

approved

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Last modified September 19 16:46 EDT 2020. Contains 337178 sequences. (Running on oeis4.)