"CIK" (necklace, indistinct, unlabeled) transform of 1,2,3,4,...

Terms

a(0) =1a(1) =3a(2) =6a(3) =13a(4) =25a(5) =58a(6) =121a(7) =283a(8) =646a(9) =1527a(10) =3601a(11) =8678a(12) =20881a(13) =50823a(14) =124054a(15) =304573a(16) =750121a(17) =1855098a(18) =4600201a(19) =11442085a(20) =28527446a(21) =71292603a(22) =178526881a(23) =447919418a(24) =1125750145a(25) =2833906683a(26) =7144450566a(27) =18036423973