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Search: id:A057438
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| A057438 |
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a(1) = 1; a(n+1) = product_{k = 1 to n} [a(k)] *sum_{j = 1 to n} [1/a(j)]. |
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+0
5
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| 1, 1, 2, 5, 27, 739, 546391, 298543324411, 89128116550480609893151, 7943821159836055611643954282977557048699079331, 63104294619459055797454850600852928915607093463575707111291209057699988334565551\ 829102647591
(list; graph; listen)
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OFFSET
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1,3
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LINKS
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Leroy Quet, Home Page (listed in lieu of email address)
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FORMULA
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a(n) = a(n-1)^2+A074056(n-2) where A074056 is partial product of A057438. Close to a(n-1)^2+a(n-1)*0.365177806085453... and 1.1087260396143829635274191...^(2^n). - Henry Bottomley (se16(AT)btinternet.com), Aug 14 2002
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EXAMPLE
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a(5) = a(1)*a(2)*a(3)*a(4)*(1/a(1) + 1/a(2) + 1/a(3) + 1/a(4)) = 1*1*2*5*(1 + 1 + 1/2 + 1/5) = 27.
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MATHEMATICA
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a[1] = 1; a[n_] := a[n] = Sum[1/a[n - k], {k, n - 1}] Product[a[n - k], {k, n - 1}]; Table[ a[n], {n, 11}] (from Robert G. Wilson v (rgwv(AT)rgwv.com), Jun 14 2005)
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CROSSREFS
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Cf. A074046, A074056, A108176.
Sequence in context: A097565 A079716 A058182 this_sequence A002795 A127357 A025170
Adjacent sequences: A057435 A057436 A057437 this_sequence A057439 A057440 A057441
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KEYWORD
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easy,nonn
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AUTHOR
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Leroy Quet Sep 08 2000
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EXTENSIONS
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More terms from Leroy Quet Sep 08 2000
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