Sum of indices of primes between powers of 2.

Terms

a(0) =1a(1) =2a(2) =7a(3) =11a(4) =45a(5) =105a(6) =325a(7) =989a(8) =3268a(9) =10125a(10) =33017a(11) =111435a(12) =369576a(13) =1277044a(14) =4362878a(15) =15233325a(16) =53647473a(17) =189461874a(18) =676856245a(19) =2422723580a(20) =8743378141a(21) =31684991912a(22) =115347765988a(23) =421763257890