Sum of all i such that ( 2 ^ i + 1 ) % 3 = 0 where i is in range [ 1 , n ] | Function to return the required sum ; Total odd numbers from 1 to n ; Sum of first n odd numbers ; Driver code
def sumN ( n ) : NEW_LINE INDENT n = ( n + 1 ) // 2 ; NEW_LINE return ( n * n ) ; NEW_LINE DEDENT n = 3 ; NEW_LINE print ( sumN ( n ) ) ; NEW_LINE