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A181861
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a(n) = gcd(n^2, n!/floor(n/2)!^2).
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3
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1, 1, 2, 3, 2, 5, 4, 7, 2, 9, 4, 11, 12, 13, 4, 45, 2, 17, 4, 19, 4, 21, 4, 23, 4, 25, 4, 27, 8, 29, 180, 31, 2, 99, 4, 175, 12, 37, 4, 117, 20, 41, 12, 43, 8, 675, 4, 47, 36, 49, 4, 153, 8, 53, 4, 55, 56, 57, 4, 59, 16
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OFFSET
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0,3
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LINKS
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FORMULA
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MAPLE
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A181861 := n -> igcd(n^2, n!/iquo(n, 2)!^2);
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MATHEMATICA
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sf[n_] := n!/Quotient[n, 2]!^2; Table[GCD[n^2, sf[n]], {n, 0, 60}] (* Jean-François Alcover, Jun 28 2013 *)
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PROG
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(Magma) [Gcd(n^2, Floor(Factorial(n)/(Factorial(Floor(n/2))^2))):n in [0..60]]; // Marius A. Burtea, Aug 03 2019
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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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