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 A327902 Nonprime squarefree numbers whose prime indices all have the same average of prime indices (A326567/A326568). 3
 1, 21, 57, 115, 133, 145, 159, 371, 393, 399, 515, 535, 565, 667, 803, 869, 917, 933, 1007, 1067, 1113, 1963, 2021, 2095, 2157, 2165, 2177, 2249, 2285, 2315, 2363, 2369, 2461, 2489, 2599, 2705, 2751, 2839, 2987, 3021, 3103, 3277, 3335, 3707, 3859, 4331, 4367 (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. The multiset of prime indices of n is row n of A112798. LINKS EXAMPLE The sequence of terms together with their prime indices begins:      1: {}     21: {2,4}     57: {2,8}    115: {3,9}    133: {4,8}    145: {3,10}    159: {2,16}    371: {4,16}    393: {2,32}    399: {2,4,8}    515: {3,27}    535: {3,28}    565: {3,30}    667: {9,10}    803: {5,21}    869: {5,22}    917: {4,32}    933: {2,64}   1007: {8,16}   1067: {5,25} MATHEMATICA primeMS[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]]; Select[Range[1000], !PrimeQ[#]&&SquareFreeQ[#]&&SameQ@@Mean/@primeMS/@primeMS[#]&]; CROSSREFS The version including primes and nonsquarefree numbers is A326536. The version for number of prime indices is A327900. The version for sum of prime indices is A327901. Cf. A001222, A005117, A056239, A078175, A102627, A112798, A316413, A326567/A326568, A326621, A327908. Sequence in context: A044123 A044504 A118057 * A020148 A037305 A223467 Adjacent sequences:  A327899 A327900 A327901 * A327903 A327904 A327905 KEYWORD nonn AUTHOR Gus Wiseman, Sep 30 2019 STATUS approved

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Last modified May 19 18:35 EDT 2022. Contains 353847 sequences. (Running on oeis4.)