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A290304 Values of uphi(k) = uphi(k+1). 1

%I #13 Nov 10 2021 07:07:23

%S 1,12,24,120,96,180,432,744,720,864,840,1200,1260,1680,2520,1728,2784,

%T 2880,3744,4032,5040,2592,4224,5040,5760,11520,11880,9216,18000,20160,

%U 17280,12480,17280,20160,28080,20160,23040,21600,32256,30240,52080,34560,57600

%N Values of uphi(k) = uphi(k+1).

%C The values of unitary totient function of numbers such that k and k+1 have the same value.

%C The unitary version of A003275.

%H Amiram Eldar, <a href="/A290304/b290304.txt">Table of n, a(n) for n = 1..2198</a>

%F a(n) = A047994(A287055(n)).

%t uphi[n_] := If[n==1, 1, (Times @@ (Table[#[[1]]^#[[2]] - 1, {1}] & /@ FactorInteger[n]))[[1]]]; a={}; u1=0; For[k=0, k<10^5, k++; u2=uphi[k]; If[u1==u2, a = AppendTo[a, u1]]; u1=u2]; a

%Y Cf. A001274, A003275, A047994, A287055.

%K nonn

%O 1,2

%A _Amiram Eldar_, Jul 26 2017

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Last modified April 24 12:39 EDT 2024. Contains 371937 sequences. (Running on oeis4.)