Numbers of the form (2^(m*r)-1)/(2^r-1) for positive integers m, r.

Terms

a(0) =1a(1) =3a(2) =5a(3) =7a(4) =9a(5) =15a(6) =17a(7) =21a(8) =31a(9) =33a(10) =63a(11) =65a(12) =73a(13) =85a(14) =127a(15) =129a(16) =255a(17) =257a(18) =273a(19) =341a(20) =511a(21) =513a(22) =585a(23) =1023a(24) =1025a(25) =1057a(26) =1365a(27) =2047a(28) =2049a(29) =4095