Consecutive primes with the same terminal digits

In response to a problem posed by Mark Underwood on the "Prime Numbers" Yahoo!Group.

139 and 149 are the smallest consecutive primes with the same terminal digit, so a(2)=139.

Here's a table of the smallest starting points for sequences of increasing length runs of primes with the same terminal digits:

I'd expect these to grow slightly faster than exponentially, so here's a log-plot of those values (doesn't include the 16):

Last modified 2006/05/23, thanks to Jens' eagle eyes.