eiru_invoiceid_voucher/data/sequence.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data noupdate="1">

        <!-- Sequences for Ñande TV-->
        <record id="seq_type_invoice_id" model="ir.sequence.type">
            <field name="name">Secuencia Ñande TV</field>
            <field name="code">account.invoice</field>
        </record>

        <record id="seq_invoice_id" model="ir.sequence">
            <field name="name">Secuencia Ñande TV</field>
            <field name="code">account.invoice</field>
            <field name="prefix">- </field>
            <field name="padding">6</field>
            <field name="company_id" eval="False"/>
        </record>

    </data>
</openerp>