offset-in-wordpress-wpquery.php

// always exclude the first story from index pages!
if (!function_exists('archive_exclude_first_post')) {
    function archive_exclude_first_post($query)
    {
        if (is_admin() || !is_archive() || !$query->is_main_query()) {
            return;
        }

        $offset = 1;
        $posts_per_page = get_option('posts_per_page');

        if ($query->is_paged) {
            $offset = $offset + 
            (($query->query_vars['paged'] - 1) * $posts_per_page);
        }

        $query->set('offset', $offset);
    }
}

add_action('pre_get_posts', 'archive_exclude_first_post');

if (!function_exists('archive_adjust_offset_pagination')) {
    function archive_adjust_offset_pagination($found_posts, $query)
    {
        if (is_admin() || !is_archive() || !$query->is_main_query()) {
            return $found_posts;
        }

        $offset = 1;
        return $found_posts - $offset;
    }
}

add_filter('found_posts', 'archive_adjust_offset_pagination', 1, 2 );

http://coke-zettelkasten.tumblr.com/post/126019556991/offset-in-wordpress-wpquery