A007318^(-1) * A133648.

Terms

a(0) =1a(1) =4a(2) =9a(3) =19a(4) =37a(5) =75a(6) =149a(7) =299a(8) =597a(9) =1195a(10) =2389a(11) =4779a(12) =9557a(13) =19115a(14) =38229a(15) =76459a(16) =152917a(17) =305835a(18) =611669a(19) =1223339a(20) =2446677a(21) =4893355a(22) =9786709a(23) =19573419a(24) =39146837a(25) =78293675a(26) =156587349a(27) =313174699a(28) =626349397a(29) =1252698795