tanh(tan(x)*tan(x))=2/2!*x^2+16/4!*x^4+32/6!*x^6-18944/8!*x^8...
A009819
tanh(tan(x)*tan(x))=2/2!*x^2+16/4!*x^4+32/6!*x^6-18944/8!*x^8...
Terms
- a(0) =0a(1) =2a(2) =16a(3) =32a(4) =-18944a(5) =-2146048a(6) =-147605504a(7) =12359002112
External references
- oeis: A009819