
    Design a function for a content moderation system that calculates the total number of unique rule combinations for identifying harmful posts, given a complexity level n. The function should only consider rule sets at even-indexed positions in the pattern matching sequence, where each position's value is determined by the binomial coefficient at that index. The sum of these selected combinations will determine the system's moderation capacity for that complexity level.
    

    
import math

def even_binomial_Coeff_Sum(n):
    """
    Design a function for a content moderation system that calculates the total number of unique rule combinations for identifying harmful posts, given a complexity level n. The function should only consider rule sets at even-indexed positions in the pattern matching sequence, where each position's value is determined by the binomial coefficient at that index. The sum of these selected combinations will determine the system's moderation capacity for that complexity level.
    

    """
import math

def even_binomial_Coeff_Sum(n):
    """
    Design a function for a content moderation system that calculates the total number of unique rule combinations for identifying harmful posts, given a complexity level n. The function should only consider rule sets at even-indexed positions in the pattern matching sequence, where each position's value is determined by the binomial coefficient at that index. The sum of these selected combinations will determine the system's moderation capacity for that complexity level.
    

    """
    return 1 << n - 1