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A058250
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GCD of n-th primorial number and its totient.
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2
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1, 2, 2, 6, 30, 30, 30, 30, 330, 2310, 2310, 2310, 2310, 2310, 53130, 690690, 20030010, 20030010, 20030010, 20030010, 20030010, 20030010, 821230410, 821230410, 821230410, 821230410, 13960916970, 739928599410, 739928599410
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OFFSET
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0,2
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LINKS
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Table of n, a(n) for n=0..28.
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FORMULA
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a(n) = GCD[A002110(n), A000010(A002110(n)] = GCD[A002110(n), A005867(n)].
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EXAMPLE
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a(6)=GCD(30030,5760)=30
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MAPLE
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[seq(igcd(product(ithprime(k), k=1..m), product(ithprime(k)-1, k=1..m)), m=1..50)];
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MATHEMATICA
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GCD[#, EulerPhi[#]]&/@Rest[FoldList[Times, 1, Prime[Range[30]]]] (* Harvey P. Dale, Dec 19 2012 *)
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CROSSREFS
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A002110, A000010, A005867.
Sequence in context: A179320 A004304 A108800 * A179929 A067644 A184312
Adjacent sequences: A058247 A058248 A058249 * A058251 A058252 A058253
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KEYWORD
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nonn
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AUTHOR
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Labos Elemer, Dec 05 2000
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STATUS
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approved
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