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A046665
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Largest prime divisor of n - smallest prime divisor of n (a(1)=0).
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12
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0, 0, 0, 0, 0, 1, 0, 0, 0, 3, 0, 1, 0, 5, 2, 0, 0, 1, 0, 3, 4, 9, 0, 1, 0, 11, 0, 5, 0, 3, 0, 0, 8, 15, 2, 1, 0, 17, 10, 3, 0, 5, 0, 9, 2, 21, 0, 1, 0, 3, 14, 11, 0, 1, 6, 5, 16, 27, 0, 3, 0, 29, 4, 0, 8, 9, 0, 15, 20, 5, 0, 1, 0, 35, 2, 17, 4, 11, 0, 3, 0, 39, 0, 5, 12, 41, 26, 9, 0, 3, 6, 21, 28, 45
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,10
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COMMENTS
| Even nonzero terms correspond to odd composite numbers that are not powers of primes. Terms of A030173 appear in this sequence infinitely often. - Alonso del Arte, Nov 27 2011
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REFERENCES
| Handbook of Number Theory, D. S. Mitrinovic et al., Kluwer, Section IV.1.
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LINKS
| T. D. Noe, Table of n, a(n) for n=1..1000
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MATHEMATICA
| f[n_]:=Transpose[FactorInteger[n]][[1]]; Table[Last[f[n]-First[f[n]]], {n, 200}] (* From Vladimir Joseph Stephan Orlovsky, Apr 08 2011 *)
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CROSSREFS
| Cf. A074320, A066048, A130064, A130065.
Sequence in context: A100257 A100573 A049087 * A100574 A056100 A141665
Adjacent sequences: A046662 A046663 A046664 * A046666 A046667 A046668
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KEYWORD
| nonn,easy,nice
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
| More terms from James A. Sellers (sellersj(AT)math.psu.edu)
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