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Search: id:A144791
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OFFSET
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1,2
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REFERENCES
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Thomas Wieder: The number of certain rankings and hierarchies formed from labeled or unlabeled elements and sets, Applied Mathematical Sciences, vol. 3, 2009, no. 55, 2707 - 2724. [From Thomas Wieder (thomas.wieder(AT)t-online.de), Nov 14 2009]
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LINKS
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Thomas Wieder, Home Page.
Thomas Wieder, (Old) Home Page.
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FORMULA
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G.f.: 1 / prod_{k=1}^{inf} (1 - x^k)^A141199(k).
Let sum_{k|n} denote a sum over all divisors k of n. Then
a(n) = (1/n) sum_{k=1}^{n-1} c(k) A141199(n-k),
with c(n)= sum_{k|n} k A141199(k).
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CROSSREFS
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A141199, A144792, A144791.
Sequence in context: A127154 A062460 A098324 this_sequence A060925 A027045 A006765
Adjacent sequences: A144788 A144789 A144790 this_sequence A144792 A144793 A144794
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KEYWORD
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nonn,new
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AUTHOR
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Thomas Wieder (thomas.wieder(AT)t-online.de), Sep 21 2008
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