Driver Code
static public void Main ( ) { int n = 3 ; Console . Write ( n + " th ▁ centered ▁ " + " octadecagonal ▁ number ▁ : ▁ " ) ; Console . WriteLine ( center_octadecagon_num ( n ) ) ; n = 13 ; Console . Write ( n + " th ▁ centered ▁ " + " octadecagonal ▁ number ▁ : ▁ " ) ; Console . WriteLine ( center_octadecagon_num ( n ) ) ; } }