a(1) = 1, a(n) = the smallest prime divisor of A138793(n).

Terms

a(0) =1a(1) =3a(2) =3a(3) =29a(4) =3a(5) =3a(6) =19a(7) =3a(8) =3a(9) =457a(10) =3a(11) =3a(12) =16087a(13) =3a(14) =3a(15) =35963a(16) =3a(17) =3a(18) =167a(19) =3a(20) =3a(21) =7a(22) =3a(23) =3a(24) =13a(25) =3a(26) =3a(27) =953a(28) =3a(29) =3