Prime Lucas 7-step numbers, A104621.

Terms

a(0) =3a(1) =7a(2) =31a(3) =127a(4) =983a(5) =122401a(6) =15231991a(7) =30341581a(8) =60439343a(9) =239818559a(10) =235883775871a(11) =935968272887