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Odd prime powers p^w (w>1) such that p^w+2 is prime.
4

%I #9 Oct 15 2013 22:30:48

%S 9,27,81,125,6561,24389,59049,161051,357911,571787,1442897,4782969,

%T 5177717,14348907,18191447,30080231,73560059,80062991,118370771,

%U 127263527,131872229,318611987,344472101,440711081,461889917,590589719,756058031,865523177

%N Odd prime powers p^w (w>1) such that p^w+2 is prime.

%H Donovan Johnson, <a href="/A053702/b053702.txt">Table of n, a(n) for n = 1..1000</a>

%F A025475(n)+2 is prime

%e Examples: powers of 3 like 9,27,81,6561,59049; powers of 5 like 125; others like 23^3=24389, 71^3=357911, 83^3=571787, 11^5=161051, ...

%t Table[Do[s=2+Prime[w]^n; If[PrimeQ[s]&&!Greater[s, 10000000000], Print[s]], {n, 2, 35}], {w, 1, 1000}]

%Y Cf. A025475, A053704.

%K nonn

%O 1,1

%A _Labos Elemer_, Feb 14 2000