Rush Sighting on The Big Bang Theory, December 2010

Here's a pseudo-Rush reference from back on December 9, 2010.  During the episode "The Alien Parasite Hypothesis" (season 4, episode 10), Sheldon Cooper says "The best number is 73. 73 is the 21st prime number. Its mirror, 37, is the 12th, and its mirror, 21, is the product of multiplying - hang on to your hats - 7 and 3. In binary, 73 is a palindrome: 1001001, which backwards is 1001001. Exactly the same." - Thanks to James McKay for the headsup!