Numbers n such that n*sigma(n) is a perfect square.

Terms

a(0) =1a(1) =40a(2) =81a(3) =135a(4) =216a(5) =224a(6) =400a(7) =819a(8) =1372a(9) =3240a(10) =3744a(11) =4650a(12) =6318a(13) =18144a(14) =21700a(15) =27930a(16) =30240a(17) =32400a(18) =32760a(19) =69312a(20) =71148a(21) =91694a(22) =111132a(23) =174592a(24) =175500a(25) =185220a(26) =215472a(27) =241395a(28) =278318a(29) =293907