f(n) : n belongs to N

In Mathematica,

Select[f, # != 0 &],

where f is a list of numbers.

Victor J. Аdlucky Raed Almomani Dauji Saha

Remark: in the case m=0 (i.e. when all fi=0), the transformed list is empty.

Hi José de Jesús Camacho Medina

Unfortunately I missed your post. Possible implementation in Wolfram Mathematica is shown in the attached picture. Of course, Mathematica's native procedure Select looks much more elegant.