Ancient Greek mathematicians called the numbers 1, 3, 6, 10, 15, 21, ... triangular numbers (1 is called the first triangular number, 3 is called the second triangular number, and so on...), it has certain rules , then what is the 24th triangular number
古希腊数学家把数1，3，6，10，15，21，…叫做三角形数(1叫做第一个三角形数，3叫做第2个三角形数，依此类推…)，它有一定的规律，那么第24个三角形数是多少
<gadget id="calculator">1 + 24</gadget>
<output>25</output>

<gadget id="calculator">24 / 2</gadget>
<output>12</output>

<gadget id="calculator">25 * 12</gadget>
<output>300</output>

<result>300</result>