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A294876
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a(n) = Product_{d|n, d>1} prime(gcd(d,n/d)).
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7
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1, 2, 2, 6, 2, 8, 2, 18, 10, 8, 2, 72, 2, 8, 8, 126, 2, 200, 2, 72, 8, 8, 2, 648, 22, 8, 50, 72, 2, 128, 2, 882, 8, 8, 8, 23400, 2, 8, 8, 648, 2, 128, 2, 72, 200, 8, 2, 31752, 34, 968, 8, 72, 2, 5000, 8, 648, 8, 8, 2, 10368, 2, 8, 200, 16758, 8, 128, 2, 72, 8, 128, 2, 2737800, 2, 8, 968, 72, 8, 128, 2, 31752, 1150, 8, 2, 10368, 8, 8, 8, 648, 2, 80000, 8, 72
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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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a(n) = Product_{d|n, d>1} A000040(gcd(d,n/d)).
Other identities. For all n >= 1:
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MATHEMATICA
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A294876[n_] := Product[Prime[GCD[d, n/d]], {d, Rest[Divisors[n]]}];
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PROG
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(PARI) A294876(n) = { my(m=1); fordiv(n, d, if(d>1, m *= prime(gcd(d, n/d)))); m; };
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CROSSREFS
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Cf. A294877 (rgs-version of this filter).
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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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