1,1

All terms are even. There is no further term up to 10000. So the prime

corresponding to the next term if it exists has more than 50200 digits.

1 and 2 are the only known numbers n (up to 10000) such that prime(n)^n+n

is prime.

Table of n, a(n) for n=1..4.

prime(2)^2-2=3^2-2=7 is prime, so 2 is in the sequence.

Do[If[PrimeQ[Prime[n]^n-n], Print[n]], {n, 50000}]

Cf. A000040.

Sequence in context: A007346 A062247 A284951 * A084744 A122547 A152132

Adjacent sequences: A171258 A171259 A171260 * A171262 A171263 A171264

nonn

Farideh Firoozbakht, Dec 07 2009

approved