Odoo-Tutorial/CatEdu/openeducat_admission/data/admission_sequence.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo noupdate="1">
        <!-- Sequences for op.admission -->
        <record id="seq_op_admission" model="ir.sequence">
            <field name="name">Admission</field>
            <field name="code">op.admission</field>
            <field name="prefix">AD</field>
            <field name="padding">3</field>
            <field name="company_id" eval="False" />
        </record>
</odoo>