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 A302594 Numbers whose prime indices other than 1 are equal prime numbers. 0
 1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 16, 17, 18, 20, 22, 24, 25, 27, 31, 32, 34, 36, 40, 41, 44, 48, 50, 54, 59, 62, 64, 67, 68, 72, 80, 81, 82, 83, 88, 96, 100, 108, 109, 118, 121, 124, 125, 127, 128, 134, 136, 144, 157, 160, 162, 164, 166, 176, 179, 191, 192 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS A prime index of n is a number m such that prime(m) divides n. LINKS EXAMPLE Entry A302242 describes a correspondence between positive integers and multiset multisystems. In this case it gives the following sequence of set systems. 01: {} 02: {{}} 03: {{1}} 04: {{},{}} 05: {{2}} 06: {{},{1}} 08: {{},{},{}} 09: {{1},{1}} 10: {{},{2}} 11: {{3}} 12: {{},{},{1}} 16: {{},{},{},{}} 17: {{4}} 18: {{},{1},{1}} 20: {{},{},{2}} 22: {{},{3}} 24: {{},{},{},{1}} MATHEMATICA primeMS[n_]:=If[n===1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]]; Select[Range[400], MatchQ[Union[DeleteCases[primeMS[#], 1]], {_?PrimeQ}|{}]&] CROSSREFS Cf. A000961, A001222, A003963, A005117, A006450, A007716, A056239, A076610, A275024, A047968, A281113, A295924, A301760, A302242, A302243. Sequence in context: A325663 A277620 A031143 * A055492 A005459 A039216 Adjacent sequences:  A302591 A302592 A302593 * A302595 A302596 A302597 KEYWORD nonn AUTHOR Gus Wiseman, Apr 10 2018 STATUS approved

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Last modified January 19 23:39 EST 2022. Contains 350467 sequences. (Running on oeis4.)