Numbers n such that tau(n)*sigma(n) divides n^2.

Terms

a(0) =1a(1) =26208a(2) =56896a(3) =293760a(4) =997920a(5) =9694080a(6) =23569920a(7) =25159680a(8) =29669760a(9) =67858560a(10) =117849600a(11) =132723360a(12) =208565280a(13) =222963840a(14) =276756480a(15) =427714560a(16) =513786240a(17) =578672640a(18) =628992000a(19) =649503360a(20) =688279680a(21) =714954240a(22) =779950080a(23) =830269440a(24) =979102080a(25) =1037266560