E.g.f.: exp(sec(x)-1) = 1 + Sum_{n>0} a(n)*x^(2*n)/(2*n)!.

A217502

E.g.f.: exp(sec(x)-1) = 1 + Sum_{n>0} a(n)*x^(2*n)/(2*n)!.

Terms

    a(0) =1a(1) =1a(2) =8a(3) =151a(4) =5123a(5) =271396a(6) =20605133a(7) =2116186801a(8) =282013329788

External references