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Search: id:A071571
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| A071571 |
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Smallest number whose square has exactly 2n+1 divisors. |
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+0
3
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| 2, 4, 8, 6, 32, 64, 12, 256, 512, 24, 2048, 36, 30, 16384, 32768, 96, 72, 262144, 192, 1048576, 2097152, 60, 8388608, 216, 768, 67108864, 288, 1536, 536870912, 1073741824, 120, 576, 8589934592, 6144, 34359738368, 68719476736, 180, 864
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OFFSET
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1,1
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COMMENT
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Only squares have an odd number of divisors.
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EXAMPLE
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a(4)=6 because it is the smallest number followed by 10,14,15,16,21,22,... whose squares have 2*4 + 1, i.e. 9 divisors.
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CROSSREFS
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Cf. A005179.
Identical to A016017 shifted left.
Adjacent sequences: A071568 A071569 A071570 this_sequence A071572 A071573 A071574
Sequence in context: A131886 A061284 A016017 this_sequence A029898 A021406 A065075
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KEYWORD
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nonn
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AUTHOR
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Lekraj Beedassy (blekraj(AT)yahoo.com), May 31 2002
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EXTENSIONS
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More terms from Vladeta Jovovic (vladeta(AT)Eunet.yu), Jun 05 2002
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