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A152143 A sixth degree product form sequence: a(n)=Product[(1 + 4*Sin[k*Pi/n]^2 + 16*Sin[k*Pi/n]^4 + 64*Sin[k*Pi/n]^6), {k, 1, Floor[(n - 1)/2]}]. 0
1, 1, 1, 40, 15, 451, 160, 4901, 1785, 55480, 20295, 630631, 230400, 7152809, 2612233, 81089800, 29614935, 919350379, 335764960, 10423396429, 3806834625, 118178205080, 43161016271, 1339876575119, 489349324800, 15191201606801 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Table of n, a(n) for n=0..25.

FORMULA

a(n)=Product[(1 + 4*Sin[k*Pi/n]^2 + 16*Sin[k*Pi/n]^4 + 64*Sin[k*Pi/ n]^6), {k, 1, Floor[(n - 1)/2]}].

MATHEMATICA

f[n_] =Product[(1 + 4*Sin[k*Pi/n]^2 + 16*Sin[k*Pi/n]^4 + 64*Sin[k*Pi/n]^6), {k, 1, Floor[(n - 1)/2]}]; a = Table[f[n], {n, 0, 30}]; Round[a]; FullSimplify[ExpandAll[a]]

CROSSREFS

Sequence in context: A126652 A181643 A117831 * A277874 A033975 A033360

Adjacent sequences:  A152140 A152141 A152142 * A152144 A152145 A152146

KEYWORD

nonn

AUTHOR

Roger L. Bagula and Gary W. Adamson, Nov 26 2008

STATUS

approved

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Last modified April 19 22:22 EDT 2019. Contains 322291 sequences. (Running on oeis4.)