A013155 exp(arctanh(x)+log(x+1))=1+2*x+3/2!*x^2+6/3!*x^3+21/4!*x^4+90/5!*x^5...

1, 2, 3, 6, 21, 90, 495, 3150, 23625, 198450, 1885275, 19646550, 225935325, 2809456650, 37927664775, 547844046750, 8491582724625, 139700231921250, 2444754058621875, 45123174910563750, 879901910755993125