Indices of primes occurring in A031134.

Terms

a(0) =3a(1) =4a(2) =5a(3) =10a(4) =17a(5) =25a(6) =31a(7) =48a(8) =190a(9) =218a(10) =328a(11) =369a(12) =740a(13) =1185a(14) =1664a(15) =2226a(16) =2227a(17) =3386a(18) =3387a(19) =4060a(20) =5950a(21) =14358a(22) =30804a(23) =31546a(24) =33610a(25) =104072a(26) =118506a(27) =325853a(28) =597312a(29) =1319946