I need to initialize a vector with the binomial coefficients. The code is like the following: for(size_t i=1; i<n;i++){ nl[i]=cln::binomial(m,m-i); } where are involved very big number, something like m=10^10 and n=10^6. My purpose is to optimize the preceding optimization by using the result of the preceding iteration, i.e. binomial(n, n-(i+1))=binomial(n, i)* (n-i)/(i+1) I tried to implement the multiplication by storing the result of of (n-i)/(i+1) in one cl_RA number, but unfortunately the performance are worst than the direct calculation. Do you have any idea how to initialize efficiently this vector? Thank you for your help, Silvestre Abruzzo