Maxima Function
skewness_gumbel (a,b)
Returns the skewness coefficient of a Gumbel(a,b) random variable, with b>0.
(%i1) load (distrib)$ (%i2) assume(b>0)$ skewness_gumbel(a,b); 12 sqrt(6) zeta(3) (%o3) ------------------ 3 %pi (%i4) numer:true$ skewness_gumbel(a,b); (%o5) 1.139547099404649
where zeta
stands for the Riemann's zeta function.