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 A087577 Smallest number k such that k^n + 3 is a prime. 1
 2, 2, 2, 2, 8, 2, 2, 4, 4, 8, 10, 2, 20, 4, 2, 2, 10, 2, 124, 46, 16, 20, 190, 14, 68, 50, 152, 2, 34, 2, 34, 122, 130, 208, 374, 46, 68, 64, 10, 28, 248, 4, 106, 230, 34, 208, 52, 34, 154, 230, 116, 302, 656, 38, 2, 10, 16, 34, 140, 140, 20, 232, 140, 28, 64, 328, 2, 98, 28, 818 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..200 EXAMPLE a(5) = 8 as 8^5 + 3= 32771 is prime, while 2^5 +3, 4^5+3 and 6^5 +3 are composite. MATHEMATICA snk[n_]:=Module[{k=1}, While[!PrimeQ[k^n+3], k++]; k]; Array[snk, 70] (* Harvey P. Dale, Mar 08 2014 *) PROG (PARI) for(j=1, 50, for (i=1, 150, if(isprime(i^j+3), print1(i, ", "); break()))) CROSSREFS Cf. A087576. Sequence in context: A295557 A327641 A066874 * A323741 A168281 A203610 Adjacent sequences: A087574 A087575 A087576 * A087578 A087579 A087580 KEYWORD nonn AUTHOR Amarnath Murthy, Sep 17 2003 EXTENSIONS More terms from Mohammed Bouayoun (bouyao(AT)wanadoo.fr), Mar 14 2004 More terms from David Wasserman, Jun 08 2005 STATUS approved

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Last modified July 19 01:31 EDT 2024. Contains 374388 sequences. (Running on oeis4.)