Please go out with his favorite treats and call. Ask your neighbors to check their garages - sheds - under stairs - decks and bushes. He's probably hiding somewhere close and feeling scared and confused. Ask your neighbors to check more than once as cats are very good at hiding.
Go out at night when it's quiet and take his favorite treats. Call him softly and listen for soft meows. Take a flashlight and look under bushes and other hiding places for reflective cat eyes.
Call Veterinary clinics and animal shelters in case someone brought him in or called about spotting him.
Don't give up - keep going out especially at night when it's quiet and calling.
I hope you find him soon.