text: Sum of the first N terms of the series 2 , 10 , 30 , 68 , ... . | Function to calculate the sum ; number of terms to be included in the sum ; find the Sum
code: < ? php function calculateSum ( $ n ) { return $ n * ( $ n + 1 ) / 2 + pow ( ( $ n * ( $ n + 1 ) / 2 ) , 2 ) ; } $ n = 3 ; echo " Sum = " ? >