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A285109
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a(n) = n multiplied by its smallest prime factor; a(1) = 1.
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7
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1, 4, 9, 8, 25, 12, 49, 16, 27, 20, 121, 24, 169, 28, 45, 32, 289, 36, 361, 40, 63, 44, 529, 48, 125, 52, 81, 56, 841, 60, 961, 64, 99, 68, 175, 72, 1369, 76, 117, 80, 1681, 84, 1849, 88, 135, 92, 2209, 96, 343, 100, 153, 104, 2809, 108, 275, 112, 171, 116, 3481, 120, 3721, 124, 189, 128, 325, 132, 4489, 136, 207
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OFFSET
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1,2
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LINKS
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FORMULA
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Other identities. For all n >= 1:
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MATHEMATICA
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a[n_] := n * FactorInteger[n][[1, 1]]; Array[a, 100] (* Amiram Eldar, Jun 30 2022 *)
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PROG
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(PARI) a(n)=if(n==1, 1, n*factor(n)[1, 1]); \\ Joerg Arndt, Oct 27 2021
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CROSSREFS
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Differs from A065642 for the first time at n=12. See A284342 for all the differing points.
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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