I'd disagree here; I still think it's quite elegant. For example, in python, it would look something like

  from itertools import combinations
  magic_square = [2,7,6,
                  9,5,1,
                  4,3,8]
  def did_user_win(moves):
    # Convert moves to magic square values
    magic_values = [magic_square[move] for move in moves]
    # Check if any sum of three moves equals 15
    for three_values in combinations(magic_values,3):
      if sum(three_values) == 15: return True
    return False