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A064449
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a(n) = gcd(Phi(n!), Phi(n^n), Phi(lcm(1..n))).
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1
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1, 1, 2, 4, 4, 16, 6, 64, 18, 64, 10, 1152, 12, 1536, 1080, 1024, 16, 442368, 18, 163840, 972, 163840, 22, 15925248, 100, 196608, 1458, 196608, 28, 4777574400, 30, 1048576, 481140, 1048576, 21000, 2293235712, 36, 37748736, 157464, 524288000
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OFFSET
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1,3
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LINKS
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FORMULA
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EXAMPLE
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n=6: a(6) = gcd(Phi(720), Phi(46656), Phi(60)) = gcd(192, 16, 15552) = 16.
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PROG
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(PARI) { L=1; for (n=1, 300, L=lcm(L, n); write("b064449.txt", n, " ", gcd(eulerphi(n!), gcd(eulerphi(n^n), eulerphi(L)))) ) } \\ Harry J. Smith, Sep 14 2009
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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