Index of 2^n in A353709.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =6a(5) =8a(6) =12a(7) =18a(8) =37a(9) =68a(10) =89a(11) =184a(12) =338a(13) =548a(14) =1029a(15) =2141a(16) =3914a(17) =7121a(18) =11830a(19) =22923a(20) =38692a(21) =75029a(22) =124846a(23) =223140a(24) =419105a(25) =807096a(26) =1385673a(27) =2636205a(28) =4649883a(29) =8759535