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

A345107

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

Terms

    a(0) =1a(1) =-1a(2) =14a(3) =-86a(4) =955a(5) =-11851a(6) =183800a(7) =-3273914a(8) =67643293a(9) =-1571615577a(10) =40838683608

External references