Sum of the series 1 , 3 , 6 , 10. . . ( Triangular Numbers ) | Function to find the sum of series ; Driver code
def seriesSum ( n ) : NEW_LINE INDENT return int ( ( n * ( n + 1 ) * ( n + 2 ) ) / 6 ) NEW_LINE DEDENT n = 4 NEW_LINE print ( seriesSum ( n ) ) NEW_LINE