Denominators in expansion of a certain Dirichlet series.

Terms

a(0) =1a(1) =5a(2) =11a(3) =16a(4) =25a(5) =31a(6) =41a(7) =55a(8) =61a(9) =71a(10) =80a(11) =81a(12) =101a(13) =121a(14) =125a(15) =131a(16) =151a(17) =155a(18) =176a(19) =181a(20) =191a(21) =205a(22) =211a(23) =241a(24) =251a(25) =256a(26) =271a(27) =275a(28) =281a(29) =305