Project Euler Problem57. Not using Rational.

def root2_series
  (1..1000).inject([[3,2]]) do |result, n|
    result << [result.last[0] + 2 * result.last[1], result.last[0] + result.last[1]]
  end
end

def bigger_numerators
  root2_series.select do |term|
    term[0].to_s.size > term[1].to_s.size
  end
end

p bigger_numerators.size