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Search: id:A080371
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| A080371 |
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a(n) = smallest x such that quotient d(x+1)/d(x) equals n, where d()=A000005, the number of divisors. |
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2
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| 2, 1, 11, 23, 47, 59, 191, 167, 179, 239, 5119, 359, 20479, 2111, 719, 839, 983039, 1259, 786431, 3023, 2879, 15359, 62914559, 3359, 22031, 266239, 6299, 6719
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OFFSET
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1,1
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FORMULA
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a(n)=Min{x : d[x+1]/d[x]=n}
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EXAMPLE
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n = 49: a(49) = 233279 = m, d[m+1] = 98,d[m] = 2, quotient = 49.
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MATHEMATICA
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t = Table[ 0, {50}]; Do[ s = DivisorSigma[0, n+1] / DivisorSigma[0, n]; If[ s < 51 && t[[s]] == 0, t[[s]] = n], {n, 1, 10^8}]; t
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CROSSREFS
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Cf. A000005, A080372.
Sequence in context: A063624 A101851 A111724 this_sequence A013019 A012904 A013015
Adjacent sequences: A080368 A080369 A080370 this_sequence A080372 A080373 A080374
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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), Feb 24 2003
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EXTENSIONS
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More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Feb 27 2003
The sequence continues: ?, 5039, ?, 7559, 156671, 6881279, 25919, 10079, ?, 5505023, ...
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