pagination vs. permalinks

permalink.js

<script type="text/javascript">
  var pagination = function(){
    var hash = window.location.hash.substr(1);

    if(hash && !document.getElementById(hash)){
      var per_page = {{ paginator.per_page }};
      var post_ids = [
        {% for post in site.posts %}
          "{{ post.id | replace:'"','\"' }}",
        {% endfor %}
      ];

      var offset = Math.floor(post_ids.indexOf(hash) / per_page) + 1;
      var redirect_to;

      if(offset > 0){ // found
        if(offset === 1){
          redirect_to = "/#" + hash
        }
        else{
          redirect_to = "/page" + offset + "/#" + hash
        }

        location.href = location.protocol + "//" + location.host + redirect_to;
      }
    }
  }

 pagination();
 window.onhashchange = pagination; // this might not work for older browsers
</script>