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A055698
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Numbers n such that n | (sigma_4(n) + phi(n)^4).
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0
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1, 2, 6, 13588, 48238, 54490, 69004, 194460, 353228, 577980, 638652, 1478962, 1882188, 2190515, 2677740, 3404598, 3875508, 8456460, 9978863, 16320458, 41199780, 45112860, 76132715, 236405988, 357846865, 682983756, 689274612, 733141332, 1185444052, 1752193128
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OFFSET
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1,2
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COMMENTS
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Sigma_4(n) is the sum of the 4th powers of the divisors of n (A001159).
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LINKS
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MATHEMATICA
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Do[If[Mod[DivisorSigma[4, n] + EulerPhi[n]^4, n]==0, Print[n]], {n, 1, 10^6}]
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PROG
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(PARI) isok(k) = (sigma(k, 4) + eulerphi(k)^4)%k == 0; \\ Jinyuan Wang, Mar 17 2020
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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