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A043343 Numbers n such that there is no k > n such that phi(k) = phi(n), where phi is Euler's totient function. 5

%I #14 Jan 01 2017 02:32:48

%S 2,6,12,18,22,30,42,46,54,58,60,62,66,90,94,98,106,118,120,126,134,

%T 138,142,150,158,162,166,174,198,206,210,214,240,242,250,254,262,270,

%U 274,276,278,282,294,298,302,318,330,334,346,348,354,358,378,382,394,398

%N Numbers n such that there is no k > n such that phi(k) = phi(n), where phi is Euler's totient function.

%H Paul Tek, <a href="/A043343/b043343.txt">Table of n, a(n) for n = 1..980</a>

%F A066659(a(n)) = 0.

%F A028476(a(n)) = a(n).

%t Flatten@ Position[#, 0] &@ Table[k = n + 1; While[And[k <= 2 n + 1, EulerPhi@ k != EulerPhi@ n], k++]; Boole[k < 2 n + 1] k, {n, 400}] (* _Michael De Vlieger_, Dec 31 2016 *)

%Y Cf. A066659.

%K nonn

%O 1,1

%A _Vladeta Jovovic_, Jan 12 2002

%E Offset corrected by _Paul Tek_, Sep 25 2015

%E Definition clarified by _Alonso del Arte_, Dec 31 2016

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Last modified March 28 14:02 EDT 2024. Contains 371254 sequences. (Running on oeis4.)