

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
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OFFSET

1,1


COMMENTS

Some of the results were computed using the PrimeFormGW (PFGW) primalitytesting 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^n2 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



