a(n) = Sum_{1 <= i, j <= n} gcd(i, j, n)^3.

Terms

a(0) =1a(1) =11a(2) =35a(3) =100a(4) =149a(5) =385a(6) =391a(7) =848a(8) =1017a(9) =1639a(10) =1451a(11) =3500a(12) =2365a(13) =4301a(14) =5215a(15) =6976a(16) =5201a(17) =11187a(18) =7219a(19) =14900a(20) =13685a(21) =15961a(22) =12695a(23) =29680a(24) =19225a(25) =26015a(26) =28107a(27) =39100a(28) =25229a(29) =57365