Positions of 1's in binary expansion of Pi/4.

Terms

a(0) =1a(1) =2a(2) =5a(3) =8a(4) =13a(5) =14a(6) =15a(7) =16a(8) =17a(9) =18a(10) =20a(11) =21a(12) =23a(13) =25a(14) =27a(15) =31a(16) =35a(17) =40a(18) =42a(19) =43a(20) =45a(21) =49a(22) =50a(23) =55a(24) =59a(25) =60a(26) =62a(27) =65a(28) =66a(29) =70