Every run length in base 2 is 2.

Terms

a(0) =3a(1) =12a(2) =51a(3) =204a(4) =819a(5) =3276a(6) =13107a(7) =52428a(8) =209715a(9) =838860a(10) =3355443a(11) =13421772a(12) =53687091a(13) =214748364a(14) =858993459a(15) =3435973836a(16) =13743895347a(17) =54975581388a(18) =219902325555a(19) =879609302220