Number of lucky numbers l between powers of 2, 2^n < l <= 2^(n+1).

Terms

a(0) =0a(1) =1a(2) =1a(3) =3a(4) =3a(5) =6a(6) =12a(7) =21a(8) =38a(9) =71a(10) =123a(11) =234a(12) =427a(13) =791a(14) =1477a(15) =2774a(16) =5222a(17) =9849a(18) =18659a(19) =35412a(20) =67410a(21) =128644a(22) =245959a(23) =471166a(24) =904186a(25) =1738238a(26) =3346542a(27) =6452030a(28) =12455921a(29) =24076458