Iterates of A122227, starting from 0.

Terms

a(0) =0a(1) =1a(2) =3a(3) =8a(4) =20a(5) =55a(6) =160a(7) =493a(8) =1579a(9) =5212a(10) =17595a(11) =60462a(12) =210749a(13) =743284a(14) =2647461a(15) =9509504