# Tetranacci Numbers in C++

C++Server Side ProgrammingProgramming

Here we will see how to generate the Tetranacci numbers using C++. The Tetranacci numbers are similar to the Fibonacci numbers, but here we are generating a term by adding four previous terms. Suppose we want to generate T(n), then the formula will be like below −

T(n) = T(n - 1) + T(n - 2) + T(n - 3) + T(n - 4)

The first few numbers to start, are {0, 1, 1, 2}

## Algorithm

tetranacci(n):
Begin
first := 0, second := 1, third := 1, fourth := 2
print first, second, third, fourth
for i in range n – 4, do
next := first + second + third + fourth
print next
first := second
second := third
third := fourth
fourth := next
done
End

## Example

Live Demo

#include<iostream>
using namespace std;
long tetranacci_gen(int n){
//function to generate n tetranacci numbers
int first = 0, second = 1, third = 1, fourth = 2;
cout << first << " " << second << " " << third << " " << fourth << " ";
for(int i = 0; i < n - 4; i++){
int next = first + second + third + fourth;
cout << next << " ";
first = second;
second = third;
third = fourth;
fourth = next;
}
}
main(){
tetranacci_gen(15);
}

## Output

0 1 1 2 4 8 15 29 56 108 208 401 773 1490 2872