Hello SeqFans, S = 1 3 8 15 26 39 56 75 98 127 158 195 236 279 326... d = 2 5 7 11 13 17 19 23 29 31 37 41 43 47 ... - start S with 1 - add the smallest prime not yet added and not already present in S Question: - What could be the ratio primes/composites of S? Best, É.