Smallest square with Hamming weight n (i.e., with exactly n 1's when written in binary).

Terms

a(0) =0a(1) =1a(2) =9a(3) =25a(4) =169a(5) =121a(6) =441a(7) =1521a(8) =2025a(9) =5625a(10) =24025a(11) =47089a(12) =109561a(13) =32761a(14) =393129a(15) =851929a(16) =1540081a(17) =6275025a(18) =15327225a(19) =27258841a(20) =41925625a(21) =127893481a(22) =243204025a(23) =385611769a(24) =998244025a(25) =1979449081a(26) =4823441401a(27) =12870221809a(28) =34324602361