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A048936 Subset of A014575 listing numbers which have exactly two such representations of the desired form. 10
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

Closely related: A020342, A014575, A080718, A280928, A144563.

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

Sequence in context: A234783 A206134 A237728 * A237066 A224583 A252208

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 August 17 06:02 EDT 2017. Contains 290635 sequences.