>this seq seems absent from the OEIS: S = 2,3,5,7,11,13,17,19,22,23,25,27,29,32,33,35,37,41,43,47,52,53,55,57,59,61,67,71,72,73,75,77, 79,83,89,97,101,103,107,109,112,... Me; You left out 31, I think? but it is still missing and I will add it Neil