a(n) = n! * Sum_{k=1..n} sigma_2(k)/(k * (n-k)!).
A356600
a(n) = n! * Sum_{k=1..n} sigma_2(k)/(k * (n-k)!).
Terms
- a(0) =1a(1) =7a(2) =38a(3) =240a(4) =1509a(5) =12115a(6) =96326a(7) =929432a(8) =9421089a(9) =108909943a(10) =1249105054a(11) =17862483320a(12) =241674418101
External references
- oeis: A356600