For generating the nav, this should work.

    {% set allEntriesByWeek = allEntries|group("postDate|date('Y-W')") %}
    {% for week, entry in allEntriesByWeek %}
        <li><a href="events/{{ week|replace('-','/') }}">{{ week }}</a></li>
    {% endfor %}

For grabbing entries (using the 'week' and 'year' variables passed via the route).

    {% set startDate = now.setISODate(year, week) %}
    {% set endDate = startDate|date_modify("+6 days") %}
    {% set entries = craft.entries.section('events').postDate('and', '>= ' ~ startDate, '<= ' ~ endDate ) %}
    {% for entry in entries %}
        {{ entry.title }}
    {% endfor %}

For pagination.

    <a href="events/{{ startDate|date_modify('+7 days')|date('Y/W') }}">Next Week</a>
    <a href="events/{{ startDate|date_modify('-7 days')|date('Y/W') }}">Previous Week</a>