Since your Odin is an indoor cat, they seldom stray far as they are very scared being outside. Somethings you can do, is go out late at night when it is quiet and shake a package of treats or put his dry food in a container and shake that, while calling his name. Put a dirty sweater or any other piece of clothing that has your smell on it out in the front and one out the back to lure him to the house. Put out some tuna in hopes that he is hungry enough to come and eat it. Also like others have said, notify all your neighbours, vets, shelters and put up flyers. Bring a flashlight out with you at night and check all around your area, under balcony's, in bushes, even shine it up in trees, while calling his name.

I hate hearing about an animal gone missing as I know exactly how you feel as one of my cats a long time ago went missing and after 48 days, I figured he was never coming back, but he did. On the 48th night, he showed up.
So please, never lose the faith.

Big time prayers on the way that your Odin comes home very soon, safe and sound and {{{{{{HUGS}}}}}} for you.