(1/(1*5))+(1/(5*9))+(1/(9*13))+…..+(1/(33*37)).
(1/(1*5))+(1/(5*9))+(1/(9*13))+…..+(1/(33*37))．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 37</gadget>
<output>1/37 = around 0.027027</output>

<gadget id="calculator">1 - (1/37)</gadget>
<output>36/37 = around 0.972973</output>

<gadget id="calculator">(1/4) * (36/37)</gadget>
<output>9/37 = around 0.243243</output>

<result>9/37 = around 0.243243</result>