G.f.: exp( Sum_{n>=1} (2^n - (-1)^n)^n * x^n/n ).
A211898
G.f.: exp( Sum_{n>=1} (2^n - (-1)^n)^n * x^n/n ).
Terms
- a(0) =1a(1) =3a(2) =9a(3) =261a(4) =13419a(5) =7867287a(6) =10444212819
External references
- oeis: A211898
A211898
G.f.: exp( Sum_{n>=1} (2^n - (-1)^n)^n * x^n/n ).