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A341478
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a(n) = sqrt( Product_{1<=j<=n-1} Product_{1<=k<=n} (4*sin(j*Pi/n)^2 + 4*sin((2*k-1)*Pi/(2*n))^2) ).
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5
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1, 1, 6, 112, 6664, 1270016, 776239200, 1522266730496, 9580300901941376, 193509323594243571712, 12545297912843041612924416, 2610531939025273190037188509696, 1743627211475190637398673259679582208
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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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MATHEMATICA
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Table[Sqrt[Product[4*Sin[j*Pi/n]^2 + 4*Sin[(2*k - 1)*Pi/(2*n)]^2, {k, 1, n}, {j, 1, n-1}]], {n, 0, 15}] // Round (* Vaclav Kotesovec, Feb 14 2021 *)
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PROG
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(PARI) default(realprecision, 120);
a(n) = round(sqrt(prod(j=1, n-1, prod(k=1, n, 4*sin(j*Pi/n)^2+4*sin((2*k-1)*Pi/(2*n))^2))));
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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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