Positions of primes in A004432.

Terms

a(0) =4a(1) =8a(2) =14a(3) =17a(4) =18a(5) =29a(6) =32a(7) =38a(8) =42a(9) =43a(10) =45a(11) =57a(12) =60a(13) =62a(14) =69a(15) =75a(16) =86a(17) =89a(18) =91a(19) =101a(20) =111a(21) =124a(22) =125a(23) =127a(24) =133a(25) =142a(26) =145a(27) =154a(28) =160a(29) =163