a(n) is the prime index of A191304(n+1).

Terms

a(0) =3a(1) =5a(2) =9a(3) =15a(4) =26a(5) =51a(6) =91a(7) =160a(8) =290a(9) =526a(10) =959a(11) =1767a(12) =3279a(13) =6113a(14) =11426a(15) =21456a(16) =40448a(17) =76548a(18) =145205a(19) =276032a(20) =526142a(21) =1004977a(22) =1924032a(23) =3689162a(24) =7086486a(25) =13633821a(26) =26269617a(27) =50680636a(28) =97899691a(29) =189336057