a(2*n) = 2*a(2*n-1), a(2*n+1) = 2*a(2*n)-1.

Terms

a(0) =1a(1) =1a(2) =2a(3) =3a(4) =6a(5) =11a(6) =22a(7) =43a(8) =86a(9) =171a(10) =342a(11) =683a(12) =1366a(13) =2731a(14) =5462a(15) =10923a(16) =21846a(17) =43691a(18) =87382a(19) =174763a(20) =349526a(21) =699051a(22) =1398102a(23) =2796203a(24) =5592406a(25) =11184811a(26) =22369622a(27) =44739243a(28) =89478486a(29) =178956971