GVY: To Ganesh, for removing obstacles:

Aum Eikdantaya vidmaheVakratunaye DhimahiTanno Buddhih Pracodayat

Another Gayatri similar to this is:
Aum Eka dantaya vidmahe
Vakra tundaya dhimahi
Tanno dantih prachodayat
Translation:

"Om. Let us meditate on Sri Ganesh, the lord with one tusk. May that great lord with curved elephant trunk inspire and illumine our mind and understanding."