Okay, I'll give the answer since I just found the ONLY other source on the internet offering up this sequence:
https://oeis.org/A160337 (follow link to uncover the answer and why).
Now, why doesn't The OEIS Foundation accept bitcoin donations?
In the mean time, I'm goin' to devise another sequence, and if it's never been expressed before, I'm naming it after myself: Bruno's Primes.
Edit: Looks like I was beat to the punch with that idea as well: [1, 2, 3, 5, 7, 11, 13, 17, 23, 31, 37, 53, 71, 73, 113, 131, 137, 173, 311, 313, 317, 373, 1373, 3137]:
http://www.mersenneforum.org/showthread.php?t=20246I was just about to have you guess the number 1373, but I discovered that there's only one number left to complete the sequence. Damn!