Expansion of tan(x)/(1+x).

Terms

a(0) =0a(1) =1a(2) =-2a(3) =8a(4) =-32a(5) =176a(6) =-1056a(7) =7664a(8) =-61312a(9) =559744a(10) =-5597440a(11) =61925632a(12) =-743107584a(13) =9682766848a(14) =-135558735872