a(n) = Sum_{k=1..n} floor(n/k) * (-n)^(k-1).

A344820

a(n) = Sum_{k=1..n} floor(n/k) * (-n)^(k-1).

Terms

    a(0) =1a(1) =0a(2) =9a(3) =-52a(4) =520a(5) =-6636a(6) =102984a(7) =-1864600a(8) =38741463a(9) =-909081740a(10) =23775986069a(11) =-685854111804

External references