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%I #10 Apr 19 2016 01:07:33
%S 2,60,390,840,2310,2910,4386,6090,10374,11220,13860,21882,33654,51090,
%T 82680,114294,140910,157080,159530,168630,203190,272514,282170,318318,
%U 332010,362670,367080,393414,403130,411990,434070,492882,499590,585390
%N Integers x such that for some integer y we have uphi(x) = uphi(y) = x-y, where uphi(n) = A047994(n) is the unitary totient function: If n = Product p_i^e_i, uphi(n) = Product (p_i^e_i - 1).
%H Donovan Johnson, <a href="/A067739/b067739.txt">Table of n, a(n) for n = 1..300</a>
%t uphi[n_] := Times@@(Power@@#-1&/@FactorInteger[n]); For[x=1, True, x++, If[uphi[y=x-(u=uphi[x])]==u, Print[{x, y}]]]
%Y Cf. A047994, A067741.
%K nonn
%O 1,1
%A _Yasutoshi Kohmoto_
%E Edited by _Dean Hickerson_, Mar 07 2002
%E Offset corrected by _Donovan Johnson_, May 04 2013
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