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A111234
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(Largest proper divisor of n) + (smallest prime divisor of n).
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2
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3, 4, 4, 6, 5, 8, 6, 6, 7, 12, 8, 14, 9, 8, 10, 18, 11, 20, 12, 10, 13, 24, 14, 10, 15, 12, 16, 30, 17, 32, 18, 14, 19, 12, 20, 38, 21, 16, 22, 42, 23, 44, 24, 18, 25, 48, 26, 14, 27, 20, 28, 54, 29, 16, 30, 22, 31, 60, 32, 62, 33, 24, 34, 18, 35, 68, 36, 26, 37, 72, 38, 74, 39
(list; graph; refs; listen; history; internal format)
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OFFSET
| 2,1
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COMMENTS
| If (but not only if) n is squarefree, then a(n) is coprime to n.
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EXAMPLE
| 12's largest proper divisor is 6. 12's smallest prime divisor is 2. So a(12) = 6 + 2 = 8.
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MATHEMATICA
| f[n_] := Divisors[n][[ -2]] + FactorInteger[n][[1, 1]]; Table[ f[n], {n, 2, 74}] (* Robert G. Wilson v *)
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CROSSREFS
| Cf. A032742, A020639.
Cf. A068319.
Sequence in context: A028263 A059179 A061117 * A014683 A166737 A088847
Adjacent sequences: A111231 A111232 A111233 * A111235 A111236 A111237
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KEYWORD
| nonn
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AUTHOR
| Leroy Quet Oct 28 2005
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EXTENSIONS
| More terms from Robert G. Wilson v (rgwv(at)rgwv.com), Oct 31 2005
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