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Search: id:A048863
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| A048863 |
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Number of nonprimes (1 and composites) in the reduced residue system of n-th primorial number (A002110). |
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+0
3
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| 1, 1, 1, 6, 142, 2518, 49836, 1012859, 24211838, 721500294, 22627459401, 844130935668, 34729870646918
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OFFSET
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1,4
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FORMULA
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A005867(n) - [ A000849(n) - A001221(A002110(n)) ] = A000010(A002110(n)) - [ A000720((A002110(n)) - n ]
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EXAMPLE
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n=3, 3rd primorial is 30, EulerPhi(30)=8, a(3)=1 since 1 is regarded here a nonprime. See A048597. n=4, 4th primorial is 210, size of its reduced residue system(RRS) is 48 of 6 is either composite or 1: {1,121,143,169,187,209}.
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CROSSREFS
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Cf. A002110, A000010, A005867, A000720, A048597, A007625, A048862.
A048683(n) = A005867(n) -A000849(n) + n.
Sequence in context: A078450 A059488 A067196 this_sequence A111839 A128785 A010043
Adjacent sequences: A048860 A048861 A048862 this_sequence A048864 A048865 A048866
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KEYWORD
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more,nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu)
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