Number theoretic aspects of a combinatorial function

L. Halbeisen and N. Hungerbühler
Notes on Number Theory and Discrete Mathematics, ISSN 1310-5132
Volume 5, 1999, Number 4, Pages 138—150
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Authors and affiliations

L. Halbeisen
Dep. of Mathematics
U.C. Berkeley Evans Hall 938
Berkeley, CA 94720 USA

N. Hungerbühler
Max-Planck Institute for Mathematics in the Sciences
Inselstrasse 22-26 04103 Leipzig Germany


We investigate number theoretic aspects of the integer sequence A000522 of Sloane’s On-Line Encyclopedia of Integer Sequences. This integer sequence counts the number of sequences without repetition one can build with n distinct objects. By introducing the notion of the “shadow” of an integer function – which is related to its divisors – we treat some number theoretic properties
of this combinatorial function and investigate the related “irregular prime


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Halbeisen L. & Hungerbühler N. (1999). Number theoretic aspects of a combinatorial function. Notes on Number Theory and Discrete Mathematics, 5(4), 138-150.

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