Number of nonnegative solutions to x^2 + y^2 + z^2 = n.

Terms

a(0) =1a(1) =3a(2) =3a(3) =1a(4) =3a(5) =6a(6) =3a(7) =0a(8) =3a(9) =6a(10) =6a(11) =3a(12) =1a(13) =6a(14) =6a(15) =0a(16) =3a(17) =9a(18) =6a(19) =3a(20) =6a(21) =6a(22) =3a(23) =0a(24) =3a(25) =9a(26) =12a(27) =4a(28) =0a(29) =12