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 A087268 Solutions to gcd(x, pi(x)) = 1, where pi is A000720. 2
 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, 42, 43, 45, 47, 49, 52, 53, 55, 57, 59, 60, 61, 65, 67, 68, 69, 70, 71, 73, 74, 76, 79, 81, 83, 84, 85, 86, 87, 88, 89, 91, 95, 97, 98, 99, 101, 103, 104, 106, 107, 109, 110, 111 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Ivan Neretin, Table of n, a(n) for n = 1..10000 EXAMPLE All primes are included. MATHEMATICA Flatten[Position[Table[GCD[w, PrimePi[w]], {w, 1, 256}], 1] PROG (PARI) isok(n) = gcd(n, primepi(n)) == 1; \\ Michel Marcus, Apr 22 2018 CROSSREFS Cf. A007053, A000720, A087266, A087267, A057809. Sequence in context: A069149 A042996 A073040 * A106765 A190785 A186290 Adjacent sequences: A087265 A087266 A087267 * A087269 A087270 A087271 KEYWORD nonn AUTHOR Labos Elemer, Sep 16 2003 STATUS approved

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Last modified March 24 08:23 EDT 2023. Contains 361455 sequences. (Running on oeis4.)