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Search: id:A107656
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| A107656 |
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Numbers n such that prime(n)=d(n)*phi(n)+1, where d(n) is number of positive divisors of n. |
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+0
1
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OFFSET
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1,2
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COMMENT
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There is no further term up to 5*10^7.
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EXAMPLE
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652245 is in the sequence because prime(652245)=d(652245)*phi(652245)+1.
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MATHEMATICA
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Do[If[Prime[n] == DivisorSigma[0, n]*EulerPhi[n] + 1, Print[n]], {n, 50000000}]
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CROSSREFS
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Cf. A104905, A107657.
Adjacent sequences: A107653 A107654 A107655 this_sequence A107657 A107658 A107659
Sequence in context: A062929 A038105 A143716 this_sequence A024595 A144804 A118308
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KEYWORD
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more,nonn
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AUTHOR
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Farideh Firoozbakht (mymontain(AT)yahoo.com), Jun 06 2005
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