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

A354341

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

Terms

    a(0) =1a(1) =4a(2) =12a(3) =38a(4) =130a(5) =557a(6) =2877a(7) =18314a(8) =136458a(9) =1180457a(10) =11389081a(11) =122833207a(12) =1446973931a(13) =18594740348a(14) =257507754524

External references