Add at least one natural number between 0 and 2015 to form an arithmetic progression. How many ways are there in total?
在0与2015之间添加至少一个自然数，构成等差数列，总共有多少种方法．
<gadget id="calculator">2_015 - 1</gadget>
<output>2_014</output>

<gadget id="calculator">2_014 / 2</gadget>
<output>1_007</output>

<result>1_007</result>