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A110192 Least k>n such that phi(k)=2*phi(n), where phi is Euler's totient function. 0

%I #3 Mar 30 2012 17:22:40

%S 3,3,5,5,15,8,13,15,13,15,25,15,35,21,17,17,51,21,37,32,35,25,69,32,

%T 41,35,37,35,87,32,61,51,41,51,65,39,73,57,65,51,123,45,129,55,65,69,

%U 141,51,129,55,85,65,159,57,123,65,73,87,177,64,143,77,73,85,97,75,161,85

%N Least k>n such that phi(k)=2*phi(n), where phi is Euler's totient function.

%F a(n)=A110179(n)+n

%t Table[k=n+1; e=EulerPhi[n]; While[EulerPhi[k] != 2e, k++ ]; k, {n, 100}]

%K nonn

%O 1,1

%A _T. D. Noe_, Jul 15 2005

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Last modified March 29 06:57 EDT 2024. Contains 371265 sequences. (Running on oeis4.)