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A109668
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Numbers n such that the sum of the digits of phi(n)^sigma(n) is divisible by n.
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0
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1, 9, 18, 35, 67, 189, 310, 475, 516, 684, 2493, 2527, 3465, 4701, 5157, 8321, 11403, 11780, 14709, 18396, 47250
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OFFSET
| 1,2
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EXAMPLE
| The digits of phi(3465)^sigma(3465) sum to 72765 and 72765 is divisible by 3465, so 3465 is in the sequence.
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MATHEMATICA
| Do[s = EulerPhi[n]^DivisorSigma[1, n]; k = Plus @@ IntegerDigits[s]; If[Mod[k, n] == 0, Print[n]], {n, 1, 10^4}]
Select[Range[50000], Divisible[Total[IntegerDigits[EulerPhi[#]^ DivisorSigma[1, #]]], #]&] (* From Harvey P. Dale, Mar 19 2011 *)
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CROSSREFS
| Sequence in context: A183444 A139591 A191268 * A051063 A173942 A162689
Adjacent sequences: A109665 A109666 A109667 * A109669 A109670 A109671
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KEYWORD
| base,more,nonn
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AUTHOR
| Ryan Propper (rpropper(AT)stanford.edu), Aug 06 2005
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EXTENSIONS
| More terms from Harvey P. Dale, Mar 19 2011.
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