The sequence (1/3), (1/2), (5/9), (7/12), (3/5), (11/18)... is arranged according to a certain law, the 2001st in the sequence What is the score.
数列(1/3)，(1/2)，(5/9)，(7/12)，(3/5)，(11/18)…，是按某种规律排列的，数列中第2001个分数是多少．
<gadget id="calculator">2_001 - 1</gadget>
<output>2_000</output>

<gadget id="calculator">2_000 * 2</gadget>
<output>4_000</output>

<gadget id="calculator">1 + 4_000</gadget>
<output>4_001</output>

<gadget id="calculator">2_000 * 3</gadget>
<output>6_000</output>

<gadget id="calculator">3 + 6_000</gadget>
<output>6_003</output>

<gadget id="calculator">4_001 / 6_003</gadget>
<output>4_001/6_003 = around 0.6665</output>

<result>4_001/6_003 = around 0.6665</result>