Index of end of n-th generation of terms in A063882.

Terms

a(0) =4a(1) =9a(2) =20a(3) =43a(4) =91a(5) =188a(6) =384a(7) =777a(8) =1564a(9) =3140a(10) =6293a(11) =12601a(12) =25218a(13) =50453a(14) =100925a(15) =201870a(16) =403762a(17) =807547