If n = 2^m*k, k odd, then a(n) = 2*m+1.

Terms

a(0) =1a(1) =3a(2) =1a(3) =5a(4) =1a(5) =3a(6) =1a(7) =7a(8) =1a(9) =3a(10) =1a(11) =5a(12) =1a(13) =3a(14) =1a(15) =9a(16) =1a(17) =3a(18) =1a(19) =5a(20) =1a(21) =3a(22) =1a(23) =7a(24) =1a(25) =3a(26) =1a(27) =5a(28) =1a(29) =3