Expansion of e.g.f.: exp(sech(x)*arctanh(x))=1+x+1/2!*x^2-3/4!*x^4+20/5!*x^5+165/6!*x^6...

A012882

Expansion of e.g.f.: exp(sech(x)*arctanh(x))=1+x+1/2!*x^2-3/4!*x^4+20/5!*x^5+165/6!*x^6...

Terms

    a(0) =1a(1) =1a(2) =1a(3) =0a(4) =-3a(5) =20a(6) =165a(7) =784a(8) =1337a(9) =26256a(10) =356745a(11) =4466176a(12) =31874997a(13) =435729216a(14) =5714452653a(15) =104111460608

External references