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 A087576 Smallest number k > 1 such that k^n+2 is prime. 5
 3, 3, 3, 3, 9, 39, 9, 3, 11, 3, 15, 9, 9, 3, 3, 15, 5, 9, 63, 15, 27, 39, 41, 3, 51, 3, 59, 75, 119, 99, 71, 141, 209, 87, 65, 3, 275, 45, 23, 21, 27, 27, 69, 477, 59, 147, 231, 1605, 9, 291, 65, 15, 75, 57, 9, 225, 119, 273, 855, 33, 77, 513, 3, 219, 75, 51, 489, 369 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Some of the results were computed using the PrimeFormGW (PFGW) primality-testing program. - Hugo Pfoertner, Nov 16 2019 LINKS Hugo Pfoertner, Table of n, a(n) for n = 1..1000 MATHEMATICA Table[k = 2; While[p = k^n + 2; ! PrimeQ[p], k++]; k, {n, 68}] (* T. D. Noe, Apr 03 2012 *) PROG (PARI) for(n=1, 68, forstep(k=3, oo, 2, if(isprime(k^n+2), print1(k, ", "); break))) \\ Hugo Pfoertner, Oct 30 2018 CROSSREFS Cf. A095302 (corresponding primes), A095303 (smallest k such that k^n-2 is prime), A095304 (corresponding primes). Sequence in context: A203564 A111575 A161836 * A337328 A201700 A087575 Adjacent sequences:  A087573 A087574 A087575 * A087577 A087578 A087579 KEYWORD nonn AUTHOR Amarnath Murthy, Sep 17 2003 EXTENSIONS Corrected and extended by Hugo Pfoertner, computed using PFGW, Jun 01 2004 a(49) corrected by T. D. Noe, Apr 03 2012 STATUS approved

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Last modified November 27 06:19 EST 2020. Contains 338678 sequences. (Running on oeis4.)