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A020342 Vampire numbers (definition 1): n has a nontrivial factorization using n's digits. +0
11
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; listen)
OFFSET

1,1

COMMENT

Nontrivial means that there must be at least two factors.

REFERENCES

Clifford A. Pickover, A Passion for Mathematics, Wiley, 2005; see p. 65.

EXAMPLE

E.g. 1395 = 31*9*5.

CROSSREFS

The following sequences are all closely related: A020342, A014575, A080718, A048936, A144563.

Sequence in context: A025388 A025389 A025380 this_sequence A009944 A104395 A109024

Adjacent sequences: A020339 A020340 A020341 this_sequence A020343 A020344 A020345

KEYWORD

nonn,base

AUTHOR

David W. Wilson (davidwwilson(AT)comcast.net)

EXTENSIONS

Edited by N. J. A. Sloane (njas(AT)research.att.com), Jan 03 2009

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.


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