JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li>1|</li>
    <li>2|</li>
    <li>3|</li>
    <li>4|</li>
    <li>4+1|</li>
    <li>4+2|</li>
    <li>4+3|</li>
    <li>4+4|</li>
    <li>2*4+1|</li>
    <li>2*4+2|</li>
    <li>2*4+3|</li>
    <li>2*4+4|</li>    
    <li>3*4+1|</li>
    <li>3*4+2|</li>
    <li>3*4+3|</li>
    <li>3*4+4|</li>
</ul>

CSS

ul li {list-style-type:none; 
    float:left;}
ul li:nth-child(4n+1){clear:left;}