Setting up the factorial prime challenge made me think again about the formats different types of prime numbers that are around. Most of the ones I've looked at are of the form kb^n+/-1 so I was wondering are there any simple formats that haven't been taken yet?
I thought, wouldn't it be interesting to look for primes in more random things, like the digits of pi? A quick search and sure enough, someone thought of that already. Similarly for e.
What about putting them together? I propose, pie primes :) That is, multiply pi and e to give 8.53973422267357..., and look for prime numbers in that.
The first pie prime is... 853. Unfortunately I only have Excel so can go to 15 digits, and I'm not sure if the last one is rounded or not so it might not count anyway. No more primes up to that point.
If I get really bored I might look up other constants and start putting them together for more interesting words to look for primes in :)