Expansion of e.g.f. sech(arcsinh(x)*arctan(x)) (only even powers).

A012633

Expansion of e.g.f. sech(arcsinh(x)*arctan(x)) (only even powers).

Terms

    a(0) =1a(1) =0a(2) =-12a(3) =360a(4) =-9968a(5) =-20160a(6) =62513088a(7) =-11126763648

External references