Sum of all i such that ( 2 ^ i + 1 ) % 3 = 0 where i is in range [ 1 , n ] | Java implementation of the approach ; Function to return the required sum ; Total odd numbers from 1 to n ; Sum of first n odd numbers ; Driver code
class GFG { static int sum ( int n ) { n = ( n + 1 ) / 2 ; return ( n * n ) ; } public static void main ( String args [ ] ) { int n = 3 ; System . out . println ( sum ( n ) ) ; } }