eferences >> custom page not found)
<h1>Oops 404!</h1>
<br><b>The page you are looking for may have been renamed or does not exist in this server.</b>
<br><br><b>You will be redirected to homepage shortly.</b>
<script>
blogger_redirect = setTimeout(function() { location.pathname= "/" }, 7000);
</script>
Related: How to automatically redirect Blogger blog
From now on visitors who land on your blogs 404 error page will be notified about the 404 error and will be redirected shortly. In the above code where 7000 is the redirection time in milliseconds which you can change it as per your wish.