\log \left(N + 1\right) - \log N
\begin{array}{l}
\mathbf{if}\;N \le 13931.9619516847724:\\
\;\;\;\;\log \left(\frac{N + 1}{N}\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{0.333333333333333315}{N} \cdot \log \left(e^{\frac{\frac{1}{N}}{N}}\right) + \left(\frac{1}{N} - \frac{\frac{0.5}{N}}{N}\right)\\
\end{array}double f(double N) {
double r46217 = N;
double r46218 = 1.0;
double r46219 = r46217 + r46218;
double r46220 = log(r46219);
double r46221 = log(r46217);
double r46222 = r46220 - r46221;
return r46222;
}
double f(double N) {
double r46223 = N;
double r46224 = 13931.961951684772;
bool r46225 = r46223 <= r46224;
double r46226 = 1.0;
double r46227 = r46223 + r46226;
double r46228 = r46227 / r46223;
double r46229 = log(r46228);
double r46230 = 0.3333333333333333;
double r46231 = r46230 / r46223;
double r46232 = 1.0;
double r46233 = r46232 / r46223;
double r46234 = r46233 / r46223;
double r46235 = exp(r46234);
double r46236 = log(r46235);
double r46237 = r46231 * r46236;
double r46238 = r46226 / r46223;
double r46239 = 0.5;
double r46240 = r46239 / r46223;
double r46241 = r46240 / r46223;
double r46242 = r46238 - r46241;
double r46243 = r46237 + r46242;
double r46244 = r46225 ? r46229 : r46243;
return r46244;
}



Bits error versus N
Results
if N < 13931.961951684772Initial program 0.1
rmApplied diff-log0.1
if 13931.961951684772 < N Initial program 59.5
Taylor expanded around inf 0.0
Simplified0.0
rmApplied sub-neg0.0
Applied distribute-rgt-in0.0
Applied associate-+l+0.0
Simplified0.0
rmApplied add-log-exp0.0
Simplified0.0
Final simplification0.1
herbie shell --seed 2020056
(FPCore (N)
:name "2log (problem 3.3.6)"
:precision binary64
(- (log (+ N 1)) (log N)))