a(n) = (2*n)!*Sum[Sum[1/(i+j),{i,1,n}],{j,1,n}].
A086881
a(n) = (2*n)!*Sum[Sum[1/(i+j),{i,1,n}],{j,1,n}].
Terms
- a(0) =1a(1) =34a(2) =1788a(3) =146256a(4) =17485920a(5) =2894002560a(6) =635331029760
External references
- oeis: A086881
A086881
a(n) = (2*n)!*Sum[Sum[1/(i+j),{i,1,n}],{j,1,n}].