Shifts left 2 places under "DIK" (bracelet, indistinct, unlabeled) transform.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =6a(6) =10a(7) =21a(8) =38a(9) =81a(10) =160a(11) =344a(12) =716a(13) =1571a(14) =3390a(15) =7548a(16) =16740a(17) =37778a(18) =85338a(19) =194894a(20) =446208a(21) =1028935a(22) =2379730a(23) =5531126a(24) =12892778a(25) =30162239a(26) =70745300a(27) =166403255a(28) =392286953a(29) =926915606