What do they have in common?
6, 10, 14, 15, 21, 22, 26, 30, 33, 34, 35, 38, 39 ...
@futurebird Composite numbers where the prime factors appear only once? I.e 6 because 2x3 are both unique, but not twelve because in 2x2x3 2 appears twice?
@futurebird So, 42 would be next in the sequence. Always 42 :)