The first word is om, but it's written o3m - that's the letter ओ (o), followed by the number ३ (3), then म् (m). It's represented this way on the flag of the Arya Samaj, a Hindu reform movement. It turns out that the 3 is the symbol for प्लुति pluti, an extra-long vowel. Wikipedia claims that it appears twice in the R̥gveda, representing question intonation, giving the example
10.129.5d adháḥ svid āsî3d upári svid āsī3t "was it above? was it below?"
But in most versions it is written as three vowels:
तिरश्चीनो विततो रश्मिरेषामधः सविदासी.अ.अ.अत |
tiraścīno vitato raśmireṣāmadhaḥ savidāsī.a.a.at |
pluti also means "overflowing, a flood; a leap, jump; capering, curvet (one of a horse's paces)".
So the next time you want to represent a long drawn-out vowel, use a 3. That way no one can accuse you of using new-fangled textspeak!