4, 6, 12, 18, 30, 42, 60, 72, 102,...
What is the next number in the above sequence?
All are even. All are multiples of 6 except the first. They thin out faster than the primes. They are one off from being a prime. In both directions. Ah ha!
They are all the number between a pair of twin primes. I hope I don't have to look far to find the next pair. Oh good, the next twin primes are 107, 109. So the next number is
108.

Posted by Jer
on 20151130 16:58:09 