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A131884
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Numbers conjectured to have an infinite, aperiodic, aliquot sequence.
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0
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276, 306, 396, 552, 564, 660, 696, 780, 828, 888, 966, 996, 1074, 1086, 1098, 1104, 1134, 1218, 1302, 1314, 1320, 1338, 1350, 1356, 1392, 1398, 1410, 1464, 1476, 1488, 1512, 1560, 1572, 1578, 1590, 1632, 1650, 1662, 1674, 1722, 1734, 1758, 1770, 1806, 1836
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| From Martin Renner, Oct 28 2011 (Begin)
There are 12 numbers up to 1000 with the five yet unknown trajectories
(1) 276 ->
306 -> 396 -> 696 -> ...
(2) 552 -> 888 -> ...
(3) 564 -> 780 -> ...
(4) 660 ->
828 ->
996 -> 1356 -> ...
(5) 966 -> 1338 -> ...
The least starting numbers 276, 552, 564, 660 and 966 for the trajectories are called Lehmer five.
There are currently 81 open end trajectories up to 10000. (End)
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LINKS
| Christophe Clavier: Aliquot sequences (with leading term < 10,000).
Wolfgang Creyaufmüller: Primzahlfamilien - aliquot sequences.
Paul Zimmermann: Aliquot sequences.
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CROSSREFS
| Cf. A098007.
Sequence in context: A121743 A084802 A003903 * A008892 A133215 A015232
Adjacent sequences: A131881 A131882 A131883 * A131885 A131886 A131887
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KEYWORD
| hard,nonn
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AUTHOR
| J. Lowell, jhbubby(AT)mindspring.com, Oct 24 2007
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EXTENSIONS
| More terms and links from Martin Renner (martin.renner(AT)gmx.net), Oct 28 2011
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