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Search: id:A068956
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| A068956 |
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Number of distinct prime factors of n^n-(n-1)^(n-1). |
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+0
5
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| 1, 1, 1, 2, 2, 1, 3, 6, 3, 1, 3, 2, 3, 3, 2, 1, 2, 3, 3, 2, 2, 3, 3, 4, 7, 4, 2, 2, 5, 4, 5, 3, 6, 4, 4, 2, 4, 7, 6, 4, 3, 4, 7, 6, 2, 7, 4, 7, 10, 6, 4
(list; graph; listen)
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OFFSET
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2,4
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FORMULA
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a(n)=A001221(A007781(n)).
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EXAMPLE
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A007781(14) = 10809131718965763 = 3 * 61^2 * 968299894201, therefore a(14) = 3.
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MATHEMATICA
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Table[ Length[ FactorInteger[n^n - (n - 1)^(n - 1)]], {n, 2, 52}]
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CROSSREFS
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Cf. A068957.
Adjacent sequences: A068953 A068954 A068955 this_sequence A068957 A068958 A068959
Sequence in context: A080955 A125231 A117919 this_sequence A124842 A134399 A094436
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KEYWORD
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nonn
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AUTHOR
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Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Mar 11 2002
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EXTENSIONS
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Edited and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Mar 15 2002
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