a(n) = Sum_{k=1..n} (k/gcd(n, k))^2.

Terms

a(0) =1a(1) =2a(2) =6a(3) =12a(4) =31a(5) =33a(6) =92a(7) =96a(8) =165a(9) =172a(10) =386a(11) =239a(12) =651a(13) =499a(14) =656a(15) =776a(16) =1497a(17) =846a(18) =2110a(19) =1262a(20) =1903a(21) =2037a(22) =3796a(23) =1867a(24) =4181a(25) =3408a(26) =4530a(27) =3673a(28) =7715a(29) =3183