Numbers that are the sum of 4 nonzero squares.

Terms

a(0) =4a(1) =7a(2) =10a(3) =12a(4) =13a(5) =15a(6) =16a(7) =18a(8) =19a(9) =20a(10) =21a(11) =22a(12) =23a(13) =25a(14) =26a(15) =27a(16) =28a(17) =30a(18) =31a(19) =33a(20) =34a(21) =35a(22) =36a(23) =37a(24) =38a(25) =39a(26) =40a(27) =42a(28) =43a(29) =44