Integers of the form k*2^m + 1 where 0 < k <= m and k is odd.

Terms

a(0) =3a(1) =5a(2) =9a(3) =17a(4) =25a(5) =33a(6) =49a(7) =65a(8) =97a(9) =129a(10) =161a(11) =193a(12) =257a(13) =321a(14) =385a(15) =513a(16) =641a(17) =769a(18) =897a(19) =1025a(20) =1281a(21) =1537a(22) =1793a(23) =2049a(24) =2561a(25) =3073a(26) =3585a(27) =4097a(28) =4609a(29) =5121