1,1

(5^2-2^2)/3=7, (5^5-2^5)/3=1031, (5^7-2^7)/3=25999, ...

a={}; Do[p=(5^n-2^n)/3; If[PrimeQ[p], AppendTo[a, p]], {n, 20^2}]; Print[a];

Sequence in context: A062841 A110718 A004807 this_sequence A101072 A144927 A159994

Adjacent sequences: A139778 A139779 A139780 this_sequence A139782 A139783 A139784

nonn

Vladimir Orlovsky (4vladimir(AT)gmail.com), May 16 2008