Expansion of sqrt( cosh(x) / cos(x) ) = Sum_{n>=0} a(n) * x^(2n) / (2n)!.

A273378

Expansion of sqrt( cosh(x) / cos(x) ) = Sum_{n>=0} a(n) * x^(2n) / (2n)!.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =31a(4) =553a(5) =18961a(6) =874203a(7) =62142991a(8) =5423159953a(9) =655008561121

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