A087577 - OEIS

%I #12 Mar 10 2014 04:20:52

%S 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,

%T 2,34,2,34,122,130,208,374,46,68,64,10,28,248,4,106,230,34,208,52,34,

%U 154,230,116,302,656,38,2,10,16,34,140,140,20,232,140,28,64,328,2,98,28,818

%N Smallest number k such that k^n + 3 is a prime.

%H Vincenzo Librandi, <a href="/A087577/b087577.txt">Table of n, a(n) for n = 1..200</a>

%e a(5) = 8 as 8^5 + 3= 32771 is prime, while 2^5 +3, 4^5+3 and 6^5 +3 are composite.

%t snk[n_]:=Module[{k=1},While[!PrimeQ[k^n+3],k++];k]; Array[snk,70] (* _Harvey P. Dale_, Mar 08 2014 *)

%o (PARI) for(j=1,50, for (i=1,150,if(isprime(i^j+3),print1(i,",");break())))

%Y Cf. A087576.

%K nonn

%O 1,1

%A _Amarnath Murthy_, Sep 17 2003

%E More terms from Mohammed Bouayoun (bouyao(AT)wanadoo.fr), Mar 14 2004

%E More terms from _David Wasserman_, Jun 08 2005