Numbers k such that the number of odd divisors of k is an odd divisor of k.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =9a(5) =16a(6) =18a(7) =32a(8) =36a(9) =64a(10) =72a(11) =128a(12) =144a(13) =225a(14) =256a(15) =288a(16) =441a(17) =450a(18) =512a(19) =576a(20) =625a(21) =882a(22) =900a(23) =1024a(24) =1089a(25) =1152a(26) =1250a(27) =1521a(28) =1764a(29) =1800