a(n) = Sum_{k=1..n} (-1)^(n-k) * Stirling1(n,k) * floor(n/k).

A309910

a(n) = Sum_{k=1..n} (-1)^(n-k) * Stirling1(n,k) * floor(n/k).

Terms

    a(0) =1a(1) =3a(2) =10a(3) =53a(4) =266a(5) =2093a(6) =14512a(7) =134705a(8) =1317724a(9) =14339429a(10) =156052942a(11) =2243410945a(12) =28893239818a(13) =421448538895

External references