Sum of first n perfect powers.

Terms

a(0) =1a(1) =5a(2) =13a(3) =22a(4) =38a(5) =63a(6) =90a(7) =122a(8) =158a(9) =207a(10) =271a(11) =352a(12) =452a(13) =573a(14) =698a(15) =826a(16) =970a(17) =1139a(18) =1335a(19) =1551a(20) =1776a(21) =2019a(22) =2275a(23) =2564a(24) =2888a(25) =3231a(26) =3592a(27) =3992a(28) =4433a(29) =4917