input: Write a function to generate a sequence where each number is 5 times the previous one.
  assert list(generate_sequence(5)) == [1, 5, 25, 125, 625]
  assert list(generate_sequence(1)) == [1]
  assert list(generate_sequence(3)) == [1, 5, 25]
output: def generate_sequence(n):
      sequence = []
      current = 1
      for _ in range(n):
          sequence.append(current)
          current *= 5
      return sequence