Person URI  
Query:
SELECT ?o ?dist ( ( SELECT COUNT ( * ) WHERE { ?o foaf:knows ?xx } ) ) WHERE
  {
    {
      SELECT ?s ?o WHERE
      {
        ?s foaf:knows ?o
      }
     }
   OPTION ( transitive, t_distinct, t_in ( ?s ) , t_out ( ?o ) , t_min ( 1 ) , t_max ( 4 ) , t_step ( 'step_no' ) as ?dist ) .
    FILTER ( ?s= <http://www.w3.org/People/Berners-Lee/card#i> )
  }
ORDER BY ?dist DESC 3 LIMIT 50