sech(sin(tanh(x)))=1-1/2!*x^2+17/4!*x^4-673/6!*x^6+48481/8!*x^8...

A012050

sech(sin(tanh(x)))=1-1/2!*x^2+17/4!*x^4-673/6!*x^6+48481/8!*x^8...

Terms

    a(0) =1a(1) =-1a(2) =17a(3) =-673a(4) =48481a(5) =-5556929a(6) =930399601a(7) =-214412110305

External references