Where can I buy a couch pillow like the one on the couch of the big bang theory

I don't know exactly where the people on the show got the pillows, but they like Pottery Barn on that show, so possibly there? Or go to sheldonshirts.com and see if there's anything there. They have things like T-shirts, belt buckles, snuggies, and flipfold boards there, I know that for sure.