A122126 Primes of form Sum[ Prime[k]^5, {k,1,n} ] or primes in A122103[n].

32353461605953, 9874820441996857, 10821208357045699, 20261841065985329, 30672624709674923, 126540093912585209, 267908140423628051, 538379772006780299, 1713808283318707391, 2413049165702037271

Offset: 1

Author

Alexander Adamchuk, Aug 20 2006

Keywords

• nonn

Comments

A122103[n] = Sum[ Prime[k]^5, {k,1,n} ] begins {32,275,3400,20207,181258,552551,1972408,4448507,...}. Indices n such that A122103[n] is prime are listed in A122125[n] = {66,148,150,164,174,214,238,264,312,328,354,440,516,536,616,624,724,744,774, 836,940,...}.

Crossrefs

Cf. A122103, A122125.

Programs

Mathematica

Select[Table[Sum[Prime[k]^5,{k,1,n}],{n,1,1000}],PrimeQ[ #1]&]

Formula

a(n) = A122103[ A122125[n] ].