JSFiddle - React, Tailwind, and code Playground

HTML

<input type='number' class="txt">
<div class="divs">

</div>

CSS

div:nth-child(even) {
    background-color:red;
}
div:nth-child(odd) {
    background-color:green;
}

JavaScript

$(".txt").on("change keyup", function() {
		$('.div1gen').remove();
		divs = $('.txt').val();
   	for(i = 0; i < divs; i++) {
	    $(".divs").append("<div class=\"div1gen\">Appended item</div>");
    }
});