E.g.f.: Sum_{n>=0} tanh(2^n*x)^n/n!.A168402E.g.f.: Sum_{n>=0} tanh(2^n*x)^n/n!.Terms a(0) =1a(1) =2a(2) =16a(3) =496a(4) =63488a(5) =32899584a(6) =68048945152External referencesoeis: A168402