[Ruby] exercise _ Triple Sequence

Write a method triple_sequence that takes in two numbers, start and length. The method should return an array representing a sequence that begins with start and is length elements long. In the sequence, every element should be 3 times the previous element. Assume that the length is at least 1.

def triple_sequence(start, length)

end

print triple_sequence(2, 4) # => [2, 6, 18, 54]
puts
print triple_sequence(4, 5) # => [4, 12, 36, 108, 324]
puts

solution

def triple_sequence(start, length)
  seq = [start]

  while seq.length < length
    seq << seq[-1] * 3
  end

  return seq
end

print triple_sequence(2, 4) # => [2, 6, 18, 54]
puts
print triple_sequence(4, 5) # => [4, 12, 36, 108, 324]
puts