Program in C language to add 2+4+8+....?

Please help me how to write a program in C to find sum of 2+4+8+....to 2 raised to power n using recession

Program in C language to add 2+4+8+....?
This uses recursion


#include %26lt;math.h%26gt;


unsigned int findSum(unsigned int n);





main()


{


int n = 3;


printf("%d\n",findSum(n));


}





unsigned int findSum(unsigned int n)


{


if(n == 0)


return 0; //this should be 1 since pow(2,0) is 1 but u asked 2+4+...ok


return (pow(2,n) + findSum(n-1));


}








please use -lm option to link with math.h since i used pow() function.


gcc xxx.c -lm
Reply:#include%26lt;stdio.h%26gt;


main()


{


int n,i,j,x,y;


printf("Number: ");


scanf("%d",%26amp;n);


for(i=0;i%26lt;=n;i++)


j=2n;


for(y=0;y%26lt;=j;y++)


x=y+j;


printf("sum: %d",x);


return 0;





}
Reply:If you want to have 10 members (else change thenumber 10)





int r=0;


int b=1;


for (i=1;i%26lt;=10;i++)


{


r+=b;


b=2*b; //or use shift command


}
Reply:Ok, this is a simple program to design so dont worry about it. First you'll need a variable called SUM which will contain the sum and through a for loop(from 1 to N) we'll increment the sum ... anyway heres the code, I've done it with C++, but you can switch it to C





int main()


{


//the sum


int sum;





//n - the inputed number-..


int n;


cin%26gt;%26gt;n;





//starting from 2 increment i by 2..which is 2, 4, 6...


for(int i = 2;i%26lt;n;i+2)


{


sum+=i;


}





//print the results out


cout%26lt;%26lt;sum;





}
Reply:for(int i=num;i%26gt;=1;i--)


{


sum += 2%26lt;%26lt;i;


}


sum +=2;





I hope this is the answer you are looking for