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A323716
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a(n) = Product_{k=0..n} (3^k + 1).
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3
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2, 8, 80, 2240, 183680, 44817920, 32717081600, 71584974540800, 469740602936729600, 9246374028206585446400, 545998386365598870609920000, 96722522147893108730806108160000, 51402410615320609490117059732766720000
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OFFSET
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0,1
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LINKS
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Table of n, a(n) for n=0..12.
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FORMULA
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a(n) ~ c * 3^(n*(n+1)/2), where c = A132323 = QPochhammer[-1, 1/3] = 3.12986803713402307587769821345767...
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MATHEMATICA
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Table[Product[3^k+1, {k, 0, n}], {n, 0, 12}]
Table[QPochhammer[-1, 3, n+1], {n, 0, 12}]
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PROG
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(PARI) a(n) = prod(k=0, n, 3^k+1); \\ Michel Marcus, Jan 25 2019
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CROSSREFS
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Cf. A034472, A028361, A132323, A323715.
Sequence in context: A134529 A289897 A134054 * A229865 A134086 A297566
Adjacent sequences: A323713 A323714 A323715 * A323717 A323718 A323719
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KEYWORD
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nonn
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AUTHOR
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Vaclav Kotesovec, Jan 25 2019
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STATUS
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approved
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