Expansion of e.g.f. sech(log(cos(x))) (even exponents only).

A012009

Expansion of e.g.f. sech(log(cos(x))) (even exponents only).

Terms

    a(0) =1a(1) =0a(2) =-3a(3) =-30a(4) =-63a(5) =12540a(6) =602877a(7) =6625710a(8) =-1991169183a(9) =-241970036520

External references