Agnipurana 25.2

25.2

namo bhagavate cādau a ā aṃ aḥ svavījakāḥ(1) /
oṅkārādyā namontāś ca namo nārāyaṇastataḥ //

with "namo bhagavate" at the beginning, a, ā, aṃ, aḥ are their respective seed-syllables; / they begin with the syllable Oṃ and end with namaḥ; and then "namo nārāyaṇāya";