Evil numbers: nonnegative integers with an even number of 1's in their binary expansion.

Terms

a(0) =0a(1) =3a(2) =5a(3) =6a(4) =9a(5) =10a(6) =12a(7) =15a(8) =17a(9) =18a(10) =20a(11) =23a(12) =24a(13) =27a(14) =29a(15) =30a(16) =33a(17) =34a(18) =36a(19) =39a(20) =40a(21) =43a(22) =45a(23) =46a(24) =48a(25) =51a(26) =53a(27) =54a(28) =57a(29) =58