a(n) = Sum_{k=0..n} C(n,k)*sigma(n,k)*sigma(n,n-k) for n>0 with a(0)=1.
A179503
a(n) = Sum_{k=0..n} C(n,k)*sigma(n,k)*sigma(n,n-k) for n>0 with a(0)=1.
Terms
- a(0) =1a(1) =2a(2) =38a(3) =352a(4) =8372a(5) =115584a(6) =4900168a(7) =109607936a(8) =5462020742a(9) =210689453568
External references
- oeis: A179503