Positions of primes in A003072.

Terms

a(0) =1a(1) =3a(2) =5a(3) =7a(4) =11a(5) =17a(6) =25a(7) =28a(8) =34a(9) =38a(10) =39a(11) =41a(12) =46a(13) =48a(14) =53a(15) =57a(16) =68a(17) =72a(18) =73a(19) =77a(20) =80a(21) =91a(22) =100a(23) =108a(24) =110a(25) =113a(26) =115a(27) =116a(28) =120a(29) =123