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A253560
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Multiply n by its largest prime factor: a(n) = A006530(n) * n.
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19
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1, 4, 9, 8, 25, 18, 49, 16, 27, 50, 121, 36, 169, 98, 75, 32, 289, 54, 361, 100, 147, 242, 529, 72, 125, 338, 81, 196, 841, 150, 961, 64, 363, 578, 245, 108, 1369, 722, 507, 200, 1681, 294, 1849, 484, 225, 1058, 2209, 144, 343, 250, 867, 676, 2809, 162, 605, 392, 1083, 1682, 3481, 300, 3721, 1922, 441
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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:
A052126(a(n)) = n. [A052126 works as an inverse function for this injection.]
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MAPLE
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end proc:
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MATHEMATICA
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a[n_] := n FactorInteger[n][[-1, 1]];
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PROG
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(PARI) a(n) = if (n==1, 1, n*vecmax(factor(n)[, 1])); \\ Michel Marcus, Feb 15 2021
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CROSSREFS
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Essentially the same as A129598, except that here we have a(1) = 1.
Cf. A070003 (same sequence without 1, sorted into ascending order).
Differs from A072995 for the first time at n=15, where a(15) = 75, while A072995(15) = 225.
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KEYWORD
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nonn,changed
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AUTHOR
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STATUS
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approved
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