a(n) = Sum_{0 < x,y,z <= n and gcd(x^2 + y^2 + z^2, n)=1} gcd(x^2 + y^2 + z^2 - 1, n).

Terms

a(0) =1a(1) =8a(2) =30a(3) =112a(4) =220a(5) =240a(6) =546a(7) =1280a(8) =1134a(9) =1760a(10) =2310a(11) =3360a(12) =4212a(13) =4368a(14) =6600a(15) =13312a(16) =9520a(17) =9072a(18) =12654a(19) =24640a(20) =16380a(21) =18480a(22) =22770a(23) =38400a(24) =42500a(25) =33696a(26) =39366a(27) =61152a(28) =47908a(29) =52800