Sum of first n term of Series 3 , 5 , 9 , 17 , 33. ... | Java script program to find sum of first n terms ; Sn = n * ( 4 * n * n + 6 * n - 1 ) / 3 ; number of terms to be included in sum ; find the Sn
function calculateSum ( n ) { return ( Math . pow ( 2 , n + 1 ) + n - 2 ) ; } let n = 4 ; document . write ( " " + calculateSum ( n ) ) ;