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 A058005 a(n) = gcd(n, binomial(2n, n)). 1
 2, 2, 2, 2, 2, 12, 2, 2, 2, 4, 2, 4, 2, 4, 30, 2, 2, 12, 2, 20, 6, 4, 2, 12, 2, 4, 2, 56, 2, 4, 2, 2, 6, 4, 14, 4, 2, 4, 2, 20, 2, 84, 2, 8, 90, 4, 2, 12, 2, 4, 6, 8, 2, 12, 2, 8, 6, 4, 2, 24, 2, 4, 6, 2, 10, 132, 2, 4, 6, 20, 2, 36, 2, 4, 30, 8, 154, 12, 2, 20, 2, 4, 2, 56, 10, 4, 6, 88, 2, 20 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS EXAMPLE a(n)=2 for values like 1,2,3,4,5,7,...; a(n)=2n for values like 6,15,...,190. CROSSREFS Cf. A001405. Sequence in context: A216844 A088050 A260725 * A095386 A060359 A029665 Adjacent sequences:  A058002 A058003 A058004 * A058006 A058007 A058008 KEYWORD nonn AUTHOR Labos Elemer, Nov 13 2000 STATUS approved

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Last modified July 17 20:45 EDT 2019. Contains 325109 sequences. (Running on oeis4.)