Numbers whose abundancy index is a power of 2.

Terms

a(0) =1a(1) =6a(2) =28a(3) =496a(4) =8128a(5) =30240a(6) =32760a(7) =2178540a(8) =23569920a(9) =33550336a(10) =45532800a(11) =142990848a(12) =1379454720a(13) =8589869056a(14) =43861478400a(15) =66433720320a(16) =137438691328a(17) =153003540480a(18) =403031236608a(19) =704575228896