a(n) is the n-th J_20-prime (Josephus_20 prime).

Terms

a(0) =2a(1) =5a(2) =30a(3) =54a(4) =81a(5) =109a(6) =149a(7) =186a(8) =513a(9) =1089a(10) =8158a(11) =8533a(12) =17178a(13) =34478a(14) =913274a(15) =976402