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Search: id:A145388
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| A145388 |
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a(n)= sum of (k,n)_* for k=1,2,...,n, where (k,n)_* is the greatest divisor of k which is a unitary divisor of n |
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+0
1
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| 1, 3, 5, 7, 9, 15, 13, 15, 17, 27, 21, 35, 25, 39, 45
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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A unitary analogue of Pillai's function A018804; another unitary analogue of A018804 is A089912
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REFERENCES
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L. Toth, The unitary analogue of Pillai's arithmetical function, Collect. Math., 40 (1989), 19-30.
L. Toth, The unitary analogue of Pillai's arithmetical function II., Notes Number Theory Discrete Math., 2 (1996), no 2, 40-46.
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FORMULA
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Multiplicative: a(p^e)=2*p^e-1 for every prime power p^e
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CROSSREFS
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Sequence in context: A107220 A098758 A029608 this_sequence A121820 A006995 A163410
Adjacent sequences: A145385 A145386 A145387 this_sequence A145389 A145390 A145391
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KEYWORD
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mult,nonn
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AUTHOR
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Laszlo Toth (ltoth(AT)ttk.pte.hu), Oct 10 2008
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