Smallest nontrivial extension of n-th cube which is a square.

Terms

a(0) =16a(1) =81a(2) =2704a(3) =6400a(4) =12544a(5) =21609a(6) =343396a(7) =512656a(8) =72900a(9) =10000a(10) =1331716a(11) =17280649a(12) =21977344a(13) =27447121a(14) =337561a(15) =409600a(16) =491331556a(17) =5832225a(18) =6859161a(19) =800041225a(20) =926106624a(21) =106481761a(22) =1216753924a(23) =1382426761a(24) =1562500