A013337 cosh(exp(x)-sec(x))=1+1/2!*x^2+5/4!*x^4-20/5!*x^5+37/6!*x^6...

1, 0, 1, 0, 5, -20, 37, -700, 1017, -28584, 83769, -1514040, 9304605, -108745468, 1172343421, -11027747380, 169643707825, -1567659515472, 28786470143025, -295814371937904, 5793951884450549, -69644639946402276