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A152119
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A product sequence: a(n)=Product[5 + 4*Cos[k*Pi/n]^2, {k, 1, (n - 1)/2}].
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1
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1, 1, 1, 6, 7, 41, 48, 281, 329, 1926, 2255, 13201, 15456, 90481, 105937, 620166, 726103, 4250681, 4976784, 29134601, 34111385, 199691526, 233802911, 1368706081, 1602508992, 9381251041, 10983760033, 64300051206, 75283811239
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,4
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FORMULA
| a(n)=Product[5 + 4*Cos[k*Pi/n]^2, {k, 1, (n - 1)/2}].
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MATHEMATICA
| a = Table[Product[5 + 4*Cos[k*Pi/n]^2, {k, 1, (n - 1)/2}], {n, 0, 30}]; Round[%] FullSimplify[ExpandAll[a]]
Denominator[NestList[(5/(5+#))&, 0, 60]] [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Apr 13 2010]
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CROSSREFS
| Sequence in context: A175167 A027021 A013627 * A041080 A042091 A047181
Adjacent sequences: A152116 A152117 A152118 * A152120 A152121 A152122
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KEYWORD
| nonn
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AUTHOR
| Roger L. Bagula and Gary W. Adamson (rlbagulatftn(AT)yahoo.com), Nov 24 2008
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