Hendecagonal number | Function to find Hendecagonal number ; Formula to calculate nth Hendecagonal number ; Driver Code
function hendecagonal_num ( n ) { return ( 9 * n * n - 7 * n ) / 2 ; } let n = 3 ; document . write ( n + " " ) ; document . write ( hendecagonal_num ( n ) + " " ) ; n = 10 ; document . write ( n + " " ) ; document . write ( hendecagonal_num ( n ) ) ;