C++ SUM - I can not finish it...

[yTqfjE8b]

Hello, can somebody help me?

I need 20(summ)k=0 for 0.1(pow k) / k!

in: DEV CPP for faktorial I have:

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main(){
float k, fakt;
  printf("Number k: ");
  scanf("%f", &k);
fakt = 1;
while (k >= 1 ){
  fakt = fakt * k;
  k = k - 1;
  }
  printf("Faktorial: %f \n", fakt);
  system("pause");
  return(0);
} 

But the problem is with number 20... If I write k = 20 I will get bad factorial...

For top 0.1(pow k) I have...

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main(){  
float a, k, i, end;
  printf("Number k: ");
  scanf("%f", &k);
a = 0.1;  
while (k >= 1 ){
  end = 1*pow(a, k);
  printf("Number %.0f: %f \n", k, end);
  k = k - 1;
  }  
  system("pause");
  return(0);
}  

This is clear...

But how Can I do all of numbers behind decimal point? Not 0.00000...

Now I need 0.1(pow k) / k!
and make a Sum for 20(summ)k=0 for 0.1(pow k) / k! ... 20 is mean as k

Here I am lost... Thank you for solution guys :-)