JSFiddle - React, Tailwind, and code Playground

by Nick Craver

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/dot-luv/jquery-ui.css">
<ol>
    <li><input type="text" /></li>
    <li><input type="text" /></li>
    <li><input type="text" /></li>
    <li><input type="text" /></li>
    <li><input type="text" /></li>
</ol>

JavaScript

$("ol input:first").keyup(function() {
    var val = parseInt(this.value, 10);
    $("ol input:gt(0)").val(isNaN(val) ? '' : function(i) { return val + i + 1; });
});