JSFiddle - React, Tailwind, and code Playground

HTML

<input data-bind="value: pages"/>
<ul data-bind="foreach: virtual_elements">
    <li data-bind='text: $index()+1'></li>
</ul>

JavaScript

function ViewModel(){
    var self = this;
    self.pages = ko.observable(3);
    self.virtual_elements = ko.computed(function(){
        var arr = [];
        for (var i=1; i<=self.pages(); i++) {
            arr.push('some');
        }
        return arr;
    });
}

ko.applyBindings(new ViewModel());