This is one of those cases where I would google if I could, but I don't know what to search for.
I've come across this symbol a few times, but I have no clue what it means or what it is called.
$$\prod$$
Furthermore, what are the $\coprod$ and $\amalg$ symbols for?
I could not list all the places I found it, but the one that sparked it was a discussion on solving the Diophantine equation, $\frac{1}{x} + \frac{1}{y} = \frac{1}{n}$.
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$\begingroup$The symbol $\Pi$ is the pi-product. It is like the summation symbol $\sum$ but rather than addition its operation is multiplication. For example, $$ \prod_{i=1}^5i=1\cdot2\cdot3\cdot4\cdot5=120 $$ The other symbol is the coproduct.
$\endgroup$ 3 $\begingroup$The uppercase Pi $\prod$ symbol stands for the $product$ operator throughout mathematics, just as the uppercase Sigma $\sum$ symbol would describe the sum operator. Think of the following analogy alliteration:
Pi is to a Product ... as Sigma is to a Sum.
$\endgroup$ $\begingroup$For example, $$\prod _{i=0}^{3}a_i=a_0\cdot a_1\cdot a_2\cdot a_3$$
This is a symbol for product similarly as $\sum$ for sum.
$\endgroup$ 2 $\begingroup$$$\prod_{i=1}^n=1\cdot2\cdot3...\cdot (n-1)\cdot n$$
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