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 A125957 Numbers n such that (2^n + 11^n)/13 is prime. 4
 3, 5, 17, 67, 83, 101, 1373, 6101, 12119, 61781 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS All terms are primes. Corresponding primes of the form (2^n + 11^n)/13 are {103, 12391, 38880540653801911, ...}. a(11) > 10^5. - Robert Price, Feb 26 2013 LINKS MATHEMATICA Do[p=Prime[n]; f=(2^p+11^p)/13; If[PrimeQ[f], Print[{p, f}]], {n, 1, 100}] PROG (PARI) is(n)=ispseudoprime((2^n+11^n)/13) \\ Charles R Greathouse IV, Feb 20 2017 CROSSREFS Cf. A000978 = numbers n such that (2^n + 1)/3 is prime. Cf. A057469 = numbers n such that (2^n + 3^n)/5 is prime. Cf. A082387 = numbers n such that (2^n + 5^n)/7 is prime. Sequence in context: A265425 A256438 A251737 * A259908 A137460 A319908 Adjacent sequences:  A125954 A125955 A125956 * A125958 A125959 A125960 KEYWORD hard,more,nonn AUTHOR Alexander Adamchuk, Feb 06 2007 EXTENSIONS 2 more terms from Ryan Propper, Feb 09 2008 a(9)-a(10) from Robert Price, Feb 26 2013 STATUS approved

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Last modified July 10 05:51 EDT 2020. Contains 335572 sequences. (Running on oeis4.)