1/exp(1/(y+1)+1/(y+2)+1/(y+3)-harmonic(3))-1,y=0.25+sum[1/n! D[(x-(1/exp(1/(x+1)+1/(x+2)+1/(x+3)-harmonic(3))-1))^n,{x,n-1}],{n,1,5}],x=0.25