E.g.f.: exp(arctan(arctan(x))) = 1+x+1/2!*x^2-3/3!*x^3-15/4!*x^4+49/5!*x^5...

A012203

E.g.f.: exp(arctan(arctan(x))) = 1+x+1/2!*x^2-3/3!*x^3-15/4!*x^4+49/5!*x^5...

Terms

    a(0) =1a(1) =1a(2) =1a(3) =-3a(4) =-15a(5) =49a(6) =609a(7) =-1859a(8) =-48031a(9) =119617a(10) =6247681a(11) =-10283171a(12) =-1214813487a(13) =678311217a(14) =330587407201a(15) =246695568861

External references