a(n) = Sum_{d|n} d*sigma_n(d).

A320940

a(n) = Sum_{d|n} d*sigma_n(d).

Terms

    a(0) =1a(1) =11a(2) =85a(3) =1127a(4) =15631a(5) =287021a(6) =5764809a(7) =135007759a(8) =3487020610a(9) =100146496681

External references