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%I #12 Apr 23 2018 08:38:19
%S 1,2,3,5,7,9,11,12,13,17,18,19,21,23,25,26,28,29,31,32,34,35,36,37,41,
%T 42,43,45,47,49,52,53,55,57,59,60,61,65,67,68,69,70,71,73,74,76,79,81,
%U 83,84,85,86,87,88,89,91,95,97,98,99,101,103,104,106,107,109,110,111
%N Solutions to gcd(x, pi(x)) = 1, where pi is A000720.
%H Ivan Neretin, <a href="/A087268/b087268.txt">Table of n, a(n) for n = 1..10000</a>
%e All primes are included.
%t Flatten[Position[Table[GCD[w, PrimePi[w]], {w, 1, 256}], 1]
%o (PARI) isok(n) = gcd(n, primepi(n)) == 1; \\ _Michel Marcus_, Apr 22 2018
%Y Cf. A007053, A000720, A087266, A087267, A057809.
%K nonn
%O 1,2
%A _Labos Elemer_, Sep 16 2003
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