exp((arctan(x))^2)=1+2/2!*x^2-4/4!*x^4+8/6!*x^6+912/8!*x^8...

A012456

exp((arctan(x))^2)=1+2/2!*x^2-4/4!*x^4+8/6!*x^6+912/8!*x^8...

Terms

    a(0) =1a(1) =2a(2) =-4a(3) =8a(4) =912a(5) =-99168a(6) =11815872a(7) =-1790856576a(8) =347783278848

External references