E.g.f.: exp(tan(arcsinh(x))).

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =5a(5) =16a(6) =61a(7) =216a(8) =937a(9) =6400a(10) =41881a(11) =125696a(12) =259181a(13) =18156672a(14) =225924245a(15) =-930421504a(16) =-25529526319a(17) =394852151296