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Search: id:A069782
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| A069782 |
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Numbers n such that g[n] := GCD[d[n^3],d[n]] = 2^w for some w. The first missing integer is 432 (See in A069781). |
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+0
4
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| 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69
(list; graph; listen)
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OFFSET
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1,2
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LINKS
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Tanya Khovanova, Non Recursions
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EXAMPLE
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Below 100000 only 314 integers are missing, collected in A069781.
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MATHEMATICA
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f[x_] := GCD[DivisorSigma[0, x^3], DivisorSigma[0, x]]; Do[s=f[n]; If[IntegerQ[Log[2, s]], Print[{n, s}]], {n, 1, 100000}]
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CROSSREFS
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Cf. A000005, A069780, A069781, A037992, A061701.
Sequence in context: A160356 A038608 A105811 this_sequence A088480 A061019 A028310
Adjacent sequences: A069779 A069780 A069781 this_sequence A069783 A069784 A069785
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KEYWORD
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nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), Apr 08 2002
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