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A216206
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a(n) = product_{i=1..n} ((-2)^i-1).
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2
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1, -3, -9, 81, 1215, -40095, -2525985, 325852065, 83092276575, -42626337882975, -43606743654283425, 89350217747626737825, 365889141676531491393375, -2997729737755822508985921375, -49111806293653640164716349886625, 1609344780436736134557590069434814625
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OFFSET
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0,2
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COMMENTS
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Signed partial products of A062510. This implies that all terms from a(1) on are multiples of 3.
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LINKS
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FORMULA
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MAPLE
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mul( (-2)^i-1, i=1..n) ;
end proc:
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MATHEMATICA
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Table[(-1)^n QPochhammer[-2, -2, n], {n, 0, 15}] (* Bruno Berselli, Mar 13 2013 *)
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CROSSREFS
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KEYWORD
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sign,easy
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AUTHOR
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STATUS
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approved
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