a(n) = Sum_{i|n,j|n} sigma(i)*sigma(j)/sigma(gcd(i,j)), where sigma(n) = sum of divisors of n.

Terms

a(0) =1a(1) =10a(2) =13a(3) =45a(4) =19a(5) =130a(6) =25a(7) =150a(8) =78a(9) =190a(10) =37a(11) =585a(12) =43a(13) =250a(14) =247a(15) =429a(16) =55a(17) =780a(18) =61a(19) =855a(20) =325a(21) =370a(22) =73a(23) =1950a(24) =174a(25) =430a(26) =358a(27) =1125a(28) =91a(29) =2470