Shifts left 2 places under "DHK" (bracelet, identity, unlabeled) transform.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =2a(6) =4a(7) =5a(8) =11a(9) =19a(10) =40a(11) =81a(12) =173a(13) =365a(14) =782a(15) =1669a(16) =3585a(17) =7690a(18) =16565a(19) =35699a(20) =77200a(21) =167197a(22) =363201a(23) =790508a(24) =1725057a(25) =3772067a(26) =8266834a(27) =18152392a(28) =39937523a(29) =88021367