Sum of the distinct prime factors of 2^n-1.

Terms

a(0) =0a(1) =0a(2) =3a(3) =7a(4) =8a(5) =31a(6) =10a(7) =127a(8) =25a(9) =80a(10) =45a(11) =112a(12) =28a(13) =8191a(14) =173a(15) =189a(16) =282a(17) =131071a(18) =102a(19) =524287a(20) =91a(21) =471a(22) =798a(23) =178528a(24) =286a(25) =2433a(26) =10925a(27) =262737a(28) =320a(29) =3425