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A300518
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The greatest prime factor of the squarefree part of n, or 1 if n is square.
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2
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1, 2, 3, 1, 5, 3, 7, 2, 1, 5, 11, 3, 13, 7, 5, 1, 17, 2, 19, 5, 7, 11, 23, 3, 1, 13, 3, 7, 29, 5, 31, 2, 11, 17, 7, 1, 37, 19, 13, 5, 41, 7, 43, 11, 5, 23, 47, 3, 1, 2, 17, 13, 53, 3, 11, 7, 19, 29, 59, 5, 61, 31, 7, 1, 13, 11, 67, 17, 23, 7, 71, 2, 73, 37
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OFFSET
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1,2
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LINKS
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FORMULA
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EXAMPLE
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For n = 15000 = 5^4 * 3 * 2^3, 3 is the greatest unpaired prime, so a(15000) = 3.
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MAPLE
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a:= n-> max(1, seq(i[1]^irem(i[2], 2), i=ifactors(n)[2])):
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MATHEMATICA
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PROG
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(PARI) gpf(n) = if (n==1, 1, vecmax(factor(n)[, 1]));
(Magma) [#f eq 0 select 1 else f[#f][1] where f is Factorization(Squarefree(n)): n in [1..90]]; // Vincenzo Librandi, Mar 08 2018
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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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