— Burt Kaliski Jr. (@modulomathy) February 27, 2012
A good starting point for answering a question about the next term in a series is to look at the differences between successive terms, which in this case is:
2 3 5 7 11 13 17 .
The math triviologist will quickly recognize the differences as the prime numbers. The next difference is 19, so the 8th term in the series is 77.