a(n) = least square such that the subsets of {a(1),...,a(n)} sum to 2^n different values.

Terms

a(0) =1a(1) =4a(2) =9a(3) =16a(4) =36a(5) =81a(6) =144a(7) =324a(8) =625a(9) =1156a(10) =2401a(11) =4900a(12) =9801a(13) =19600a(14) =39204a(15) =78400a(16) =156816a(17) =313600a(18) =627264a(19) =1254400a(20) =2509056a(21) =5022081a(22) =10042561a(23) =20088324a(24) =40182921a(25) =80371225a(26) =160731684a(27) =321484900a(28) =642977449a(29) =1285939600