%I #5 Mar 30 2012 17:31:16

%S 17,5,3,11,11,3,677,17,3,83,23,3,5,29,3,1049,23,3,307,41,3,5,5,3,41,

%T 53,3,523347633027360537213687137,59,3,11,5,3,227,71,3,630023,101,3,

%U 29,47,3,5,89,3,1957243,11,3,251,101,3,5,5,3,29,113,3,1289,11,3,701,5,3,307

%N Smallest factor of 3^(2n)+(2n)^3.

%C For n=1 and 28 we have the only two known cases where 3^(2n)+(2n)^3 is prime: 17 and 523347633027360537213687137. Cases n=3*m are trivial and may be omitted.

%C There are no further cases when 3^(2n)+(2n)^3 is prime up to n = 3500. Hugo Pfoertner, Jun 25 2005

%C n = 5056 gives a probable prime. Hans Havermann, Jun 24 2005

%t Table[With[{k=3}, FactorInteger[n^k+k^n]][[1, 1]], {n, 2, 100, 2}]

%Y Cf. A109216.

%K base,nonn

%O 1,1

%A _Zak Seidov_, Jun 24 2005

%E More terms from _Robert G. Wilson v_, Jun 25 2005