I know this was the example for the idea journal, but I didn't really start thinking about it until I got to the book. I wondered, why is it only evens? I thought about it and figured that odd numbers could only be the sum of an odd and even prime, namely 2 and some other prime. This doesn't work well for isolated primes, does it? :)

I was wondering, however, if any even integer could be expressed as the sum of a different number of primes. Increasing the number of primes will make some integers seem trivial — you can always add up a string of 2's — but seeing as the integers are infinite, who knows about the larger ones!