"CFJ" (necklace, size, labeled) transform of 2,2,2,2...

Terms

a(0) =1a(1) =2a(2) =2a(3) =14a(4) =18a(5) =62a(6) =1046a(7) =1934a(8) =7538a(9) =33278a(10) =1290822a(11) =2916014a(12) =14298246a(13) =64274862a(14) =430953854a(15) =30305249534a(16) =83399665778a(17) =474765871742