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%I #13 Oct 01 2016 15:25:11
%S 1,2,4,2,66,26,6,18,8,126,48,38,144,696,38,234,666,60,4,228,216,212,
%T 168,290,6,702,14,78,120,614,222,44,104,66,58,54,152,260,858,74,108,
%U 164,336,152,424,60,118,1154,112,14,1530,14,296,654,1782,474,444,462,1338,468
%N Minimal number m such that prime(1)^n + ... + prime(m)^n is prime.
%H Charles R Greathouse IV, <a href="/A121819/b121819.txt">Table of n, a(n) for n = 1..1000</a>
%e a(1) = 1 because 2 = 2^1 is prime. a(2) = 2 because 13 = 2^2 + 3^2 is prime but 2^2 is not prime. a(3) = 4 because 503 = 2^3 + 3^3 + 5^3 + 7^3 is prime but 8 = 2^3, 35 = 2^3 + 3^3, 160 = 2^3 + 3^3 + 5^3 are not prime.
%o (PARI) a(n)=my(m, s); forprime(p=2, , m++; if(isprime(s+=p^n), return(m))) \\ _Charles R Greathouse IV_, Sep 25 2016
%K nonn
%O 1,2
%A _Alexander Adamchuk_, Aug 26 2006
%E Name edited by _Charles R Greathouse IV_, Sep 25 2016
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