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Search: id:A072074
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| A072074 |
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Number of solutions to EulerPhi[x]=10^n. |
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+0
1
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OFFSET
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1,1
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FORMULA
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Card{x : A000010(x)=10^n}=nops(invphi(10^n)).
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EXAMPLE
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n=3: a(3)=11 because InvPhi(1000)= {1111, 1255, 1375, 1875, 2008, 2222, 2500, 2510, 2750, 3012, 3750}.
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MAPLE
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[seq(nops(invphi(10^i)), i=1..8)];
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CROSSREFS
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Cf. A000010, A014197, A014573.
Adjacent sequences: A072071 A072072 A072073 this_sequence A072075 A072076 A072077
Sequence in context: A002382 A023168 A134419 this_sequence A024819 A005822 A018625
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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), Jun 13 2002
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