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A097419
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a(1) = 2, a(n) = 2*a(n-1)^2 - a(n-1) for n > 1.
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2
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OFFSET
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1,1
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COMMENTS
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These numbers when factored are 2*3, 2*3*11, 2*3*11*131, 2*3*11*131*17291, 2*3*11*131*17291*298995971, 2*3*11*131*8779*10079*17291*298995971*1010341471, 2*3*11*29*59*131*241*8779*10079*17291*298995971*1010341471*2511683491*7716660340023314591, so a(n) is a prime multiple of a(n-1) for 2<=n<=6. 2,3,11,131,17291,298995971 are A090475 [Beginning with 2, a(n+1) is the least prime == -1 (mod (product a(i), i=1 to n)).]
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LINKS
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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