Sum of (any number of) distinct squares: of form r^2 + s^2 + t^2 + ... with 0 <= r < s < t < ...

Terms

a(0) =0a(1) =1a(2) =4a(3) =5a(4) =9a(5) =10a(6) =13a(7) =14a(8) =16a(9) =17a(10) =20a(11) =21a(12) =25a(13) =26a(14) =29a(15) =30a(16) =34a(17) =35a(18) =36a(19) =37a(20) =38a(21) =39a(22) =40a(23) =41a(24) =42a(25) =45a(26) =46a(27) =49a(28) =50a(29) =51