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A174809
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A (100,-196) Somos 4 sequence.
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3
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1, 4, 68, 3664, 559296, 292983296, 677028302848, 5742750182014976, 140199451387306704896, 10334993471103615132237824, 3076052900280004094541239943168, 3864163084421857020112275272686895104
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OFFSET
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0,2
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COMMENTS
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LINKS
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FORMULA
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a(n) = (100*a(n-1)*a(n-3) - 196*a(n-2)^2)/a(n-4), n>3.
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MATHEMATICA
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RecurrenceTable[{a[n] == (100*a[n-1]*a[n-3] -196*a[n-2]^2)/a[n-4], a[0] == 1, a[1] == 4, a[2] == 68, a[3] == 3664}, a, {n, 0, 20}] (* G. C. Greubel, Sep 18 2018 *)
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PROG
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(PARI) m=20; v=concat([1, 4, 68, 3664], vector(m-4)); for(n=5, m, v[n] = ( 100*v[n-1]*v[n-3] - 196*v[n-2]^2)/v[n-4]); v \\ G. C. Greubel, Sep 18 2018
(Magma) I:=[1, 4, 68, 3664]; [n le 4 select I[n] else (100*Self(n-1)*Self(n-3) - 196*Self(n-2)^2)/Self(n-4): n in [1..20]]; // G. C. Greubel, Sep 18 2018
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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