Location of 0's when natural numbers are listed in binary.

Terms

a(0) =0a(1) =3a(2) =7a(3) =8a(4) =10a(5) =14a(6) =19a(7) =20a(8) =21a(9) =23a(10) =24a(11) =27a(12) =29a(13) =31a(14) =36a(15) =37a(16) =40a(17) =45a(18) =51a(19) =52a(20) =53a(21) =54a(22) =56a(23) =57a(24) =58a(25) =61a(26) =62a(27) =64a(28) =66a(29) =67