orden_cobro/orden_cobro_sequence.xml

<openerp>
    <data noupdate="1">

        <!-- Sequences for repair.workorder -->
        <record id="seq_type_ordencobro" model="ir.sequence.type">
            <field name="name">Orden de cobro</field>
            <field name="code">orden.cobro</field>
        </record>

        <record id="seq_orden_cobro" model="ir.sequence">
            <field name="name">Orden de cobro</field>
            <field name="code">orden.cobro</field>
            <field name="prefix">0</field>
            <field name="padding">7</field>
            <field name="company_id" eval="False"/>
        </record>

    </data>
</openerp>