functions.php

function exclude_content_landing_page() {
if ( is_single() && !is_page_template('landing.php') )  
    echo '<div class="custom-content">Add Adsense Code Here</div>';
};
/**
* @author Brad Dalton
* @learn more http://wpsites.net/web-design/code-snippets-for-adding-custom-functions/
*/
add_action('genesis_before_content_sidebar_wrap', 'exclude_content_landing_page');