Iterates of A122237 starting from the initial value 8.

Terms

a(0) =8a(1) =20a(2) =57a(3) =167a(4) =569a(5) =1832a(6) =5693a(7) =19241a(8) =72004a(9) =251434a(10) =817685a(11) =2912603a(12) =11464927a(13) =41520649a(14) =137255398a(15) =502535651a(16) =2038965137a(17) =7539964485a(18) =25351037019a(19) =94403539934a(20) =389919393256