Octacontagon Number | C ++ program for above approach ; Finding the nth octacontagon Number ; Driver Code
#include <bits/stdc++.h> NEW_LINE using namespace std ; int octacontagonNum ( int n ) { return ( 78 * n * n - 76 * n ) / 2 ; } int main ( ) { int n = 3 ; cout << "3rd ▁ octacontagon ▁ Number ▁ is ▁ = ▁ " << octacontagonNum ( n ) ; return 0 ; }