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A104354
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Euler's totient of A104350(n).
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1
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1, 1, 2, 4, 16, 48, 288, 576, 1728, 8640, 86400, 259200, 3110400, 21772800, 108864000, 217728000, 3483648000, 10450944000, 188116992000, 940584960000, 6584094720000, 72425041920000, 1593350922240000, 4780052766720000, 23900263833600000, 310703429836800000
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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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MATHEMATICA
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EulerPhi[FoldList[Times, Array[FactorInteger[#][[-1, 1]] &, 30]]] (* Amiram Eldar, Apr 08 2024 *)
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PROG
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(PARI) gpf(n) = my(f=factor(n)[, 1]); f[#f];
a(n) = eulerphi(prod(i=2, n, gpf(i))); \\ Michel Marcus, Nov 12 2023
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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