undesirable icon

Dear,

I download WPeCounter plugin. It is a user counter. I work just with pages, static home page and menu. The plugin did not work. So I deleted it from WP and wp-content. Unfortunatelly it let a icon and a number that does not desappear.
My site is squadrimathematics.com and the HTML commands let by the pluggin are:

<img src=”http://i1.wp.com/www.squadrimathematics.com/wp-content/plugins/wp-user-tracker/templates/assets/img/online.png?w=474&#8243; width=”32″ height=”32″>

<span class=”usercounts”>1</span>

How could you help me?

Antonio Squadri