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A071571
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Smallest number whose square has exactly 2n+1 divisors.
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2
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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
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Only squares have an odd number of divisors.
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EXAMPLE
| 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
| Cf. A005179.
Identical to A016017 shifted left.
Sequence in context: A131886 A061284 A016017 * A201568 A029898 A153130
Adjacent sequences: A071568 A071569 A071570 * A071572 A071573 A071574
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KEYWORD
| nonn
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AUTHOR
| Lekraj Beedassy (blekraj(AT)yahoo.com), May 31 2002
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EXTENSIONS
| More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Jun 05 2002
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