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A220371
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a(n) = Product_{i=1..2*n} (4*i+2)*A060818(n).
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3
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1, 60, 30240, 17297280, 70572902400, 112634352230400, 518118020259840000, 1622745639453818880000, 53122201253160214855680000, 275173002491369912952422400000, 3520013047869603926487387340800000, 27244900990510734391012378017792000000
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OFFSET
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0,2
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LINKS
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FORMULA
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MAPLE
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a := proc(n): denom(binomial(1/2, iquo(n, 2)))*product((4*i+2), i=1..2*n) end: seq(a(n), n=0..11); # Johannes W. Meijer, Dec 21 2012
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MATHEMATICA
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a[n_] := 2^(2n)*Product[2i+1, {i, 1, 2n}]*GCD[n!, 2^n]; Table[a[n], {n, 0, 11}] (* Jean-François Alcover, Dec 21 2012 *)
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PROG
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(Sage)
@CachedFunction
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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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