\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}\frac{1 \cdot {\left(\frac{1}{k}\right)}^{\frac{1}{4}}}{\sqrt{\sqrt{k}}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}double f(double k, double n) {
double r142909 = 1.0;
double r142910 = k;
double r142911 = sqrt(r142910);
double r142912 = r142909 / r142911;
double r142913 = 2.0;
double r142914 = atan2(1.0, 0.0);
double r142915 = r142913 * r142914;
double r142916 = n;
double r142917 = r142915 * r142916;
double r142918 = r142909 - r142910;
double r142919 = r142918 / r142913;
double r142920 = pow(r142917, r142919);
double r142921 = r142912 * r142920;
return r142921;
}
double f(double k, double n) {
double r142922 = 1.0;
double r142923 = 1.0;
double r142924 = k;
double r142925 = r142923 / r142924;
double r142926 = 0.25;
double r142927 = pow(r142925, r142926);
double r142928 = r142922 * r142927;
double r142929 = sqrt(r142924);
double r142930 = sqrt(r142929);
double r142931 = r142928 / r142930;
double r142932 = 2.0;
double r142933 = atan2(1.0, 0.0);
double r142934 = r142932 * r142933;
double r142935 = n;
double r142936 = r142934 * r142935;
double r142937 = r142922 - r142924;
double r142938 = r142937 / r142932;
double r142939 = pow(r142936, r142938);
double r142940 = r142931 * r142939;
return r142940;
}



Bits error versus k



Bits error versus n
Results
Initial program 0.4
rmApplied add-sqr-sqrt0.4
Applied sqrt-prod0.5
Applied associate-/r*0.5
Taylor expanded around 0 0.4
Final simplification0.4
herbie shell --seed 2020042
(FPCore (k n)
:name "Migdal et al, Equation (51)"
:precision binary64
(* (/ 1 (sqrt k)) (pow (* (* 2 PI) n) (/ (- 1 k) 2))))