text: Enneadecagonal number | C # program to find nth Enneadecagonal number ; Function to calculate Enneadecagonal number ; Formula for finding nth Enneadecagonal number ; Driver Code
code: using System ; class GFG { static int nthEnneadecagonal ( int n ) { return ( 17 * n * n - 15 * n ) / 2 ; } static public void Main ( ) { int n = 6 ; Console . Write ( n + " th ▁ Enneadecagonal ▁ number ▁ : " ) ; Console . WriteLine ( nthEnneadecagonal ( n ) ) ; } }