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A058825 Numbers which are both totients and cototients. 1

%I

%S 1,2,4,6,8,12,16,18,20,22,24,28,30,32,36,40,42,44,46,48,54,56,60,64,

%T 66,70,72,78,80,82,84,88,92,96,102,104,106,108,110,112,120,126,128,

%U 132,136,138,140,144,148,150,156,160,162,164,166,168,176,178,180,184,190

%N Numbers which are both totients and cototients.

%H Donovan Johnson, <a href="/A058825/b058825.txt">Table of n, a(n) for n = 1..10000</a>

%F Intersection(A002202, A051953).

%e 24 is here because 24 = phi(72) = 44-phi(44) = 44-20 = cototient(44).

%Y Cf. A000010, A051953, A005277, A005278, A002020, A058763.

%K nonn

%O 1,2

%A _Labos Elemer_, Jan 04 2001

%E Offset corrected by _Donovan Johnson_, Nov 17 2013

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Last modified January 18 16:27 EST 2020. Contains 331011 sequences. (Running on oeis4.)