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Search: id:A061708
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| A061708 |
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Smallest number the square of which has (2n-1)^2 divisors. |
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+0
1
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| 1, 6, 36, 216, 210, 7776, 46656, 1260, 1679616, 10077696, 7560, 362797056, 44100, 18480, 78364164096, 470184984576, 272160, 264600, 101559956668416, 1632960, 3656158440062976, 21936950640377856, 180180, 789730223053602816, 9261000
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OFFSET
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1,2
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COMMENT
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a(n)<=36^(n-1) which have also (2n-1)^2 divisors.
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FORMULA
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a(n)=Min{x|d(x^2)=(2n-1)^2} a(n)=Min{x|A000005[A000290(x)=A000290[A005408(n)]}
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EXAMPLE
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n = 8, a(8) = 1260 = 2.2.3.3.5.7 and d[1260^2] = d[2.2.2.2.3.3.3.3.5.5.7.7] = (2.8-1)^2 = 15^2 = 225 n = 14, a(14) = 18480 and d[2.2.2.2.2.2.2.2.3.5.7.11] = (2n-1)^2 = 729.
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CROSSREFS
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Cf. A000290, A000005, A005408, A025281, A048691, A005179, A016017.
Sequence in context: A052748 A074436 A036162 this_sequence A124535 A007274 A126634
Adjacent sequences: A061705 A061706 A061707 this_sequence A061709 A061710 A061711
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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), Jun 19 2001
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EXTENSIONS
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More terms from David Wasserman (wasserma(AT)spawar.navy.mil), Jun 24 2002
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