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A091339
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a(n) = a(n-1)*a(n-2) + (n-2); a(1) = 1, a(2) = 2.
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1
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1, 2, 3, 8, 27, 220, 5945, 1307906, 7775501177, 10169624642405370, 79073928376671158546120499, 804152170591192270227367107671577224679640, 63587471141272584754077292003976884470033921630214659882200111940371
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OFFSET
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1,2
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COMMENTS
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a(19) is a composite number with 1217 digits, and it has no prime factors < 10^9. - Jianing Song, Nov 25 2023
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LINKS
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MATHEMATICA
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a[1] = 1; a[2] = 2; a[n_] := a[n - 1]a[n - 2] + n - 2; Table[ a[n], {n, 13}] (* Robert G. Wilson v, Dec 10 2004 *)
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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Martti V. A. Holopainen (martti.holopainen(AT)pp2.inet.fi), Dec 06 2004
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EXTENSIONS
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STATUS
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approved
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