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A020342
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Vampire numbers (definition 1): n has a nontrivial factorization using n's digits.
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12
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126, 153, 688, 1206, 1255, 1260, 1395, 1435, 1503, 1530, 1827, 2187, 3159, 3784, 6880, 10251, 10255, 10426, 10521, 10525, 10575, 11259, 11439, 11844, 11848, 12006, 12060, 12384, 12505, 12546, 12550, 12595, 12600, 12762, 12768, 12798, 12843, 12955, 12964
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Nontrivial means that there must be at least two factors.
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REFERENCES
| Clifford A. Pickover, A Passion for Mathematics, Wiley, 2005; see p. 65.
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EXAMPLE
| E.g. 1395 = 31*9*5.
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CROSSREFS
| The following sequences are all closely related: A020342, A014575, A080718, A048936, A144563.
Sequence in context: A025388 A025389 A025380 * A179482 A009944 A203566
Adjacent sequences: A020339 A020340 A020341 * A020343 A020344 A020345
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KEYWORD
| nonn,base
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AUTHOR
| David W. Wilson (davidwwilson(AT)comcast.net)
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EXTENSIONS
| Edited by N. J. A. Sloane (njas(AT)research.att.com), Jan 03 2009
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