a(n) = prime(n)^7.

Terms

a(0) =128a(1) =2187a(2) =78125a(3) =823543a(4) =19487171a(5) =62748517a(6) =410338673a(7) =893871739a(8) =3404825447a(9) =17249876309a(10) =27512614111a(11) =94931877133a(12) =194754273881a(13) =271818611107a(14) =506623120463