a(n) = Sum_{k=1..n} H(k) k! (n-k)!, where H(k) is the k-th harmonic number.
A091530
a(n) = Sum_{k=1..n} H(k) k! (n-k)!, where H(k) is the k-th harmonic number.
Terms
- a(0) =1a(1) =4a(2) =16a(3) =73a(4) =388a(5) =2396a(6) =17024a(7) =137544a(8) =1248816a(9) =12603288a(10) =140018688a(11) =1698063552a(12) =22318009344a(13) =315942698880
External references
- oeis: A091530