Numbers k such that the square of d(k) (number of divisors) divides k.

Terms

a(0) =1a(1) =9a(2) =128a(3) =625a(4) =972a(5) =1152a(6) =2000a(7) =2025a(8) =5625a(9) =6561a(10) =7776a(11) =8100a(12) =10000a(13) =10800a(14) =18000a(15) =21952a(16) =26244a(17) =30000a(18) =32768a(19) =35721a(20) =50625a(21) =55296a(22) =56700a(23) =64000a(24) =64800a(25) =65856a(26) =70000a(27) =80000a(28) =84672a(29) =89100