Position of rightmost 0 (including leading 0) in 2^n increases.

Terms

a(0) =0a(1) =4a(2) =7a(3) =13a(4) =14a(5) =18a(6) =24a(7) =27a(8) =31a(9) =34a(10) =37a(11) =49a(12) =51a(13) =67a(14) =72a(15) =76a(16) =77a(17) =81a(18) =86a(19) =129a(20) =176a(21) =229a(22) =700a(23) =1757a(24) =1958a(25) =7931a(26) =57356a(27) =269518a(28) =411658a(29) =675531