Well... according to the link you provided. When I view the source, I see
<link rel="icon" href="favicon.ico" type="image/x-icon">
but your favicon is located here: http://54.235.78.67/codeMath/images/logo.ico
Here your path is wrong and the filename Is also wrong. Try using this:
<link rel="icon" type="image/ico" href="images/logo.ico">