\log \left(N + 1\right) - \log N
\begin{array}{l}
\mathbf{if}\;N \le 9772.093561518631759099662303924560546875:\\
\;\;\;\;\log \left(\frac{N + 1}{N}\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{0.3333333333333333148296162562473909929395}{{N}^{3}} + \frac{1}{\frac{N}{1 - \frac{0.5}{N}}}\\
\end{array}double f(double N) {
double r44465 = N;
double r44466 = 1.0;
double r44467 = r44465 + r44466;
double r44468 = log(r44467);
double r44469 = log(r44465);
double r44470 = r44468 - r44469;
return r44470;
}
double f(double N) {
double r44471 = N;
double r44472 = 9772.093561518632;
bool r44473 = r44471 <= r44472;
double r44474 = 1.0;
double r44475 = r44471 + r44474;
double r44476 = r44475 / r44471;
double r44477 = log(r44476);
double r44478 = 0.3333333333333333;
double r44479 = 3.0;
double r44480 = pow(r44471, r44479);
double r44481 = r44478 / r44480;
double r44482 = 1.0;
double r44483 = 0.5;
double r44484 = r44483 / r44471;
double r44485 = r44474 - r44484;
double r44486 = r44471 / r44485;
double r44487 = r44482 / r44486;
double r44488 = r44481 + r44487;
double r44489 = r44473 ? r44477 : r44488;
return r44489;
}



Bits error versus N
Results
if N < 9772.093561518632Initial program 0.1
rmApplied diff-log0.1
if 9772.093561518632 < N Initial program 59.6
Taylor expanded around inf 0.0
Simplified0.0
rmApplied clear-num0.0
Final simplification0.1
herbie shell --seed 2019303
(FPCore (N)
:name "2log (problem 3.3.6)"
:precision binary64
(- (log (+ N 1)) (log N)))