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A048936 Subset of A014575 listing numbers which have exactly two such representations of the desired form. 9
125460, 11930170, 12054060, 12417993, 12600324, 12827650, 13002462, 22569480, 23287176, 26198073, 26373600, 26839800, 46847920, 61360780, 1001795850, 1013265360, 1017509850, 1018172470, 1044022896, 1047395790 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

REFERENCES

C. A. Pickover, "Vampire Numbers." Ch. 30 in Keys to Infinity. New York: Wiley, pp. 227-231, 1995.

LINKS

Table of n, a(n) for n=1..20.

Eric Weisstein's World of Mathematics, Vampire Number.

EXAMPLE

125460 = 204*615=246*510

11930170 = 1301*9170=1310*9107

12054060 = 2004*6015=2406*5010

CROSSREFS

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

Cf. A014575, A048933, ..., A048939.

Sequence in context: A234783 A206134 A237728 * A237066 A224583 A175691

Adjacent sequences:  A048933 A048934 A048935 * A048937 A048938 A048939

KEYWORD

nonn,base

AUTHOR

Eric W. Weisstein

EXTENSIONS

Edited by N. J. A. Sloane, Jan 03 2009

STATUS

approved

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Last modified October 24 09:28 EDT 2014. Contains 248516 sequences.