E.g.f.: 1/sqrt(cos(x)*cosh(x) - sin(x)*sinh(x)), omitting the zero-valued coefficients of odd powers of x.

A185071

E.g.f.: 1/sqrt(cos(x)*cosh(x) - sin(x)*sinh(x)), omitting the zero-valued coefficients of odd powers of x.

Terms

    a(0) =1a(1) =1a(2) =11a(3) =311a(4) =17401a(5) =1605121a(6) =221150291a(7) =42544269431

External references