real_estate_base/data/rental_agreement_sequence.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
<data noupdate="1">
    
    <record id="seq_type_rental_agreement" model="ir.sequence.type">
        <field name="name">Rental Agreement Code</field>
        <field name="code">rental.agreement</field>
    </record>
    <record id="rental_agreement_seq" model="ir.sequence">
        <field name="name">Rental Agreement Code</field>
        <field name="code">rental.agreement</field>
        <field name="number_next">1</field>
        <field name="padding">6</field>
    </record>

</data>
</openerp>