a(n) = Sum_{d|n} (-1)^(n/d+1)*d^(d-1).

A321386

a(n) = Sum_{d|n} (-1)^(n/d+1)*d^(d-1).

Terms

    a(0) =1a(1) =1a(2) =10a(3) =61a(4) =626a(5) =7768a(6) =117650a(7) =2097085a(8) =43046731a(9) =999999376a(10) =25937424602a(11) =743008362964

External references