Shifts left 2 places under "EFK" (unordered, size, unlabeled) transform.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =2a(6) =4a(7) =6a(8) =10a(9) =17a(10) =29a(11) =50a(12) =88a(13) =156a(14) =279a(15) =498a(16) =909a(17) =1639a(18) =3010a(19) =5495a(20) =10152a(21) =18674a(22) =34745a(23) =64312a(24) =120197a(25) =223850a(26) =420057a(27) =785683a(28) =1480429a(29) =2779462