G.f.: Sum_{n>=0} (2*n)! * x^n / Product_{k=1..2*n} (1 + k*x).
A208885
G.f.: Sum_{n>=0} (2*n)! * x^n / Product_{k=1..2*n} (1 + k*x).
Terms
- a(0) =1a(1) =2a(2) =18a(3) =494a(4) =26730a(5) =2360462a(6) =307793178a(7) =55540518014
External references
- oeis: A208885