G.f.: Sum_{n>=0} arctanh(4^n*x)^n/n!, a power series in x having only integer coefficients.
A141368
G.f.: Sum_{n>=0} arctanh(4^n*x)^n/n!, a power series in x having only integer coefficients.
Terms
- a(0) =1a(1) =4a(2) =128a(3) =43712a(4) =178978816
External references
- oeis: A141368