describe Integer, "#coprime?" do
  # A053674 
  @seq = [7,11,11,11,11,13,13,7,17,17,17,11,11,11,7,11,13,
          13,13,13,17,7,11,11,11,11,11,13,7,13,13,13,13,11,
          11,7,11,11,17,13,13,13,7,13,11,11,11,11,11,7,19,
          17,13,13,13,11,7,11,11,11,17,17,19,7,19,13,11,11,
          11,11,7,13]
  
  @seq.each_slice(2) do |a, b|
    next if a == b
    it "should return true for co-prime pair #{a} and #{b}" do
      a.coprime?(b).should be_true
    end

    c = a * rand(100)
    d = b * c

    it "should return false for non-co-prime pair #{c} and #{d}" do
      c.coprime?(d).should be_false
    end
  end

  it "should return false if self is equal to the argument" do
    3.coprime?(3).should be_false
  end
end