"DFK" (bracelet, size, unlabeled) transform of 1,2,3,4...

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =7a(5) =15a(6) =25a(7) =43a(8) =64a(9) =120a(10) =234a(11) =348a(12) =615a(13) =995a(14) =1817a(15) =4060a(16) =6039a(17) =10505a(18) =17947a(19) =30268a(20) =52289a(21) =122862a(22) =175180a(23) =311547a(24) =502859a(25) =860833a(26) =1359388a(27) =2391385a(28) =5262510a(29) =7592091