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Search: id:A115170
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| A115170 |
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Non-cube-free numbers n such that 2n+1 is also non-cube-free (A046099). |
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+0
2
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| 40, 256, 312, 472, 688, 904, 1120, 1200, 1312, 1336, 1552, 1768, 1984, 2187, 2200, 2312, 2416, 2456, 2632, 2848, 3064, 3280, 3312, 3429, 3496, 3712, 3928, 3944, 4144, 4312, 4360, 4576, 4792, 5008, 5224, 5312, 5440, 5562, 5656, 5872, 6088, 6304
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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See also A005384 (n and 2n+1 are prime).
See also A111153 (n and 2n+1 are semiprime).
See also A117204 (n and 2n+1 are square-free).
The probability that a random integer is cube-free is 1/zeta(3) (see A088453).
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EXAMPLE
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312 is there because 2^3 divides 312 and 5^3 divides 312*2+1.
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CROSSREFS
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Cf. A000040, A001358, A005384, A046099, A088453, A111153, A117204, A115228.
Sequence in context: A074360 A068790 A073962 this_sequence A035099 A065255 A061993
Adjacent sequences: A115167 A115168 A115169 this_sequence A115171 A115172 A115173
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KEYWORD
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easy,nonn
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AUTHOR
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Jonathan Vos Post (jvospost3(AT)gmail.com), Mar 03 2006
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EXTENSIONS
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Edited by Don Reble (djr(AT)nk.ca), Mar 05 2006
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