Given a string of digits, output all the contiguous substrings of length <code class="rounded dark:bg-gray-800 dark:text-white text-black bg-gray-100 px-[0.25rem] py-[0.1rem] text-sm font-normal font-mono" data-prestyled="true">n</code> in 
that string in the order that they appear.
For example, the string "49142" has the following 3-digit series:
<ul>
<li>"491"</li>
<li>"914"</li>
<li>"142"</li>
</ul>
And the following 4-digit series:
<ul>
<li>"4914"</li>
<li>"9142"</li>
</ul>
And if you ask for a 6-digit series from a 5-digit string, you deserve 
whatever you get.
Note that these series are only required to occupy adjacent positions 
in the input; the digits need not be numerically consecutive.

Series