foreach ($results as $k => $v) {
        $html .= '
        <tr>
        <td>'.$v->nosso_numero.'</td>
        <td>'.$v->ocorrencia.'</td>
        <td>R$'.number_format($v->vlr_boleto, 2, ',', '.').'</td>
        <td>'.$v->matricula.'</td>
        <td>'.$v->nome.'</td>
        <td>'.$v->competencia.'</td>
        <td>R$'.number_format($v->valor_devido, 2, ',', '.').'</td>
        </tr>
';
    }

$results[n]->nosso_numero != $results[n-1]->nosso_numero

if($k > 1)

if($results[$k] !=$results[$k-1])

if($k > 1 && $results[$k] !=$results[$k-1])

foreach ($results as $k => $v) {
    if($k > 1 && $results[$k] !=$results[$k-1]){
        echo $v."n";
    }
}

$newResults = array_unique($results);