a(n) is the smallest number m from A173977 for which A020639(2m-1) = prime(n).

Terms

a(0) =5a(1) =13a(2) =25a(3) =127a(4) =85a(5) =196a(6) =181a(7) =472a(8) =421a(9) =946a(10) =685a(11) =1210a(12) =925a(13) =1105a(14) =1882a(15) =3157a(16) =1861a(17) =2446a(18) =2521a(19) =3541a(20) =4306a(21) =4690a(22) =3961a(23) =6160a(24) =5707a(25) =5305a(26) =5725a(27) =6922a(28) =9436a(29) =8065