The sequence of numbers involved is sometimes referred to as the hailstone sequence or hailstone numbers (because the values are normally subject to multiple descents and ascents like hailstones in a cloud), or as wondrous numbers. It is also known as the 3n + 1 problem, the 3n + 1 conjecture, the Ulam conjecture (after StanisÅ‚aw Ulam), Kakutani's problem (after Shizuo Kakutani), the Thwaites conjecture (after Sir Bryan Thwaites), Hasse's algorithm (after Helmut Hasse), or the Syracuse problem.

COMING SOON!

```
/*
collatz conjecture: a series for a number n in which if n even then the next number is n/2 ,but if n is odd then the next number is 3n+1.
this series continues till it reaches 1*/
#include<stdio.h>
int main()
{
int n,curr_no;
scanf("%d",&n); //input number
curr_no=n; //curr_no stores input number n
while(curr_no!=1) //loop till series reaches 1
{
if(curr_no%2==0) //condition for even number
{
curr_no=curr_no/2;
printf("%d->",curr_no);
}
else
{
curr_no=(curr_no*3)+1; //condition for odd number
printf("%d->",curr_no);
}
}
printf("1");
return 0;
}
```