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 A324697 Lexicographically earliest sequence of positive integers > 1 that are prime or whose prime indices already belong to the sequence. 18
 2, 3, 5, 7, 9, 11, 13, 15, 17, 19, 23, 25, 27, 29, 31, 33, 37, 41, 43, 45, 47, 51, 53, 55, 59, 61, 67, 69, 71, 73, 75, 79, 81, 83, 85, 89, 93, 97, 99, 101, 103, 107, 109, 113, 115, 121, 123, 125, 127, 131, 135, 137, 139, 141, 149, 151, 153, 155, 157, 163, 165 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 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..61. EXAMPLE The sequence of terms together with their prime indices begins: 2: {1} 3: {2} 5: {3} 7: {4} 9: {2,2} 11: {5} 13: {6} 15: {2,3} 17: {7} 19: {8} 23: {9} 25: {3,3} 27: {2,2,2} 29: {10} 31: {11} 33: {2,5} 37: {12} 41: {13} 43: {14} 45: {2,2,3} MATHEMATICA aQ[n_]:=Switch[n, 1, False, _?PrimeQ, True, _, And@@Cases[FactorInteger[n], {p_, k_}:>aQ[PrimePi[p]]]]; Select[Range[100], aQ] CROSSREFS Complement of A324705. Cf. A000002, A000720, A001222, A001462, A007097, A055396, A061395, A079000, A079254, A109298, A112798, A276625, A277098, A304360. Cf. A324694, A324695, A324696, A324698, A324699, A324700, A324701, A324702, A324703, A324704. Sequence in context: A213511 A092919 A005357 * A082664 A342008 A095737 Adjacent sequences: A324694 A324695 A324696 * A324698 A324699 A324700 KEYWORD nonn AUTHOR Gus Wiseman, Mar 10 2019 STATUS approved

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Last modified November 30 02:46 EST 2023. Contains 367452 sequences. (Running on oeis4.)