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A249570 Conjectured values of least number k such that k^k + n^n is prime, or 0 if no such k exists. 1

%I #11 Nov 16 2014 14:29:21

%S 1,1,2,1,0,25,2,157,0,7,48,23,40,3,4,25,0,7,70,31,74,57,12,203,4,945,

%T 14,33,0,0,20,93,28,193,2442,0,728,183,70,13,0,0,2,13,0,0,0,11,0,0,0,

%U 0,0,0,14,0,22,0,0,0,72,109,0,85,0,73,0,0,0,19,0,61,12,21,4,0,570,0,0,177,1532,0,0,55,64,75,602,151,0,133,0,0,32,33,3786,0,122,0,0

%N Conjectured values of least number k such that k^k + n^n is prime, or 0 if no such k exists.

%C The zero entries are only conjectural.

%C a(5) > 10000 or 0. Other a(n) = 0 entries have been checked up to k = 7500.

%C If a(i) = j, then a(j) <= i.

%o (PARI) a(n)=k=1;while(!ispseudoprime(k^k+n^n),k++);k

%K nonn,hard,more

%O 1,3

%A _Derek Orr_, Nov 01 2014

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