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 A324704 Lexicographically earliest sequence containing 1 and all numbers > 2 divisible by prime(m) for some m already in the sequence. 21
 1, 4, 6, 7, 8, 10, 12, 13, 14, 16, 17, 18, 19, 20, 21, 22, 24, 26, 28, 29, 30, 32, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 46, 48, 49, 50, 51, 52, 53, 54, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 70, 71, 72, 73, 74, 76, 77, 78, 79, 80, 82, 84 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS A self-describing sequence, similar to A304360. A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798. LINKS Table of n, a(n) for n=1..66. EXAMPLE The sequence of terms together with their prime indices begins: 1: {} 4: {1,1} 6: {1,2} 7: {4} 8: {1,1,1} 10: {1,3} 12: {1,1,2} 13: {6} 14: {1,4} 16: {1,1,1,1} 17: {7} 18: {1,2,2} 19: {8} 20: {1,1,3} 21: {2,4} 22: {1,5} 24: {1,1,1,2} 26: {1,6} 28: {1,1,4} MATHEMATICA aQ[n_]:=Switch[n, 1, True, 2, False, _, !And@@Cases[FactorInteger[n], {p_, k_}:>!aQ[PrimePi[p]]]]; Select[Range[100], aQ] CROSSREFS Complement of A324698. Cf. A000002, A000720, A001222, A001462, A007097, A055396, A061395, A079000, A079254, A109298, A112798, A276625, A277098, A304360. Cf. A324694, A324695, A324696, A324697, A324699, A324700, A324701, A324702, A324703, A324705. Sequence in context: A247359 A305415 A105432 * A203168 A284820 A284623 Adjacent sequences: A324701 A324702 A324703 * A324705 A324706 A324707 KEYWORD nonn AUTHOR Gus Wiseman, Mar 11 2019 STATUS approved

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Last modified September 22 00:10 EDT 2023. Contains 365503 sequences. (Running on oeis4.)