describe Integer, "#lucas_carmichael?" do
  # A006972
  @seq = [399, 935, 2015, 2915, 4991, 5719, 7055, 8855, 12719, 18095, 
          20705, 20999, 22847, 29315, 31535, 46079, 51359, 60059, 
          63503, 67199, 73535, 76751, 80189, 81719, 88559, 90287, 
          104663, 117215, 120581, 147455, 152279, 155819, 162687, 
          191807].to_seq

  @seq.each do |n|
    it "returns true for Lucas-Carmichael number #{n}" do
      n.should be_lucas_carmichael
    end
  end

  @seq.invert.sample(10).each do |n|
    it "returns false for non-Lucas-Carmichael number #{n}" do
      n.should_not be_lucas_carmichael
    end
  end
end