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A087268
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Solutions to gcd(x, pi(x)) = 1, where pi is A000720.
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2
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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
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refs;
listen;
history;
text;
internal format)
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OFFSET
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1,2
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LINKS
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Ivan Neretin, Table of n, a(n) for n = 1..10000
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EXAMPLE
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All primes are included.
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MATHEMATICA
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Flatten[Position[Table[GCD[w, PrimePi[w]], {w, 1, 256}], 1]
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PROG
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(PARI) isok(n) = gcd(n, primepi(n)) == 1; \\ Michel Marcus, Apr 22 2018
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CROSSREFS
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Cf. A007053, A000720, A087266, A087267, A057809.
Sequence in context: A069149 A042996 A073040 * A106765 A190785 A186290
Adjacent sequences: A087265 A087266 A087267 * A087269 A087270 A087271
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KEYWORD
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nonn
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AUTHOR
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Labos Elemer, Sep 16 2003
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STATUS
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approved
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