"CHK" (necklace, identity, unlabeled) transform of 1, 2, 3, 4, ...

Terms

a(0) =1a(1) =2a(2) =5a(3) =10a(4) =24a(5) =50a(6) =120a(7) =270a(8) =640a(9) =1500a(10) =3600a(11) =8610a(12) =20880a(13) =50700a(14) =124024a(15) =304290a(16) =750120a(17) =1854400a(18) =4600200a(19) =11440548a(20) =28527320a(21) =71289000a(22) =178526880a(23) =447910470a(24) =1125750120a(25) =2833885800a(26) =7144449920a(27) =18036373140a(28) =45591631800a(29) =115381697740