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A112969
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a(n) = a(n-1)^4 + a(n-2)^4 for n >= 2 with a(0) = 0, a(1) = 1.
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10
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OFFSET
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0,4
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COMMENTS
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A quartic Fibonacci sequence.
This is the quartic (or biquadratic) analog of the Fibonacci sequence similarly to A000283 being the quadratic analog of the Fibonacci sequence. The primes in this sequence begin a(3), a(4), a(5).
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LINKS
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FORMULA
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a(n) ~ c^(4^n), where c = 1.0111288972169538887655499395580320278253918666919181401824606983217263409... . - Vaclav Kotesovec, Dec 18 2014
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EXAMPLE
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a(3) = 1^4 + 1^4 = 2.
a(4) = 1^4 + 2^4 = 17.
a(5) = 2^4 + 17^4 = 83537.
a(6) = 17^4 + 83537^4 = 48698490414981559682.
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MATHEMATICA
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RecurrenceTable[{a[1] ==1, a[2] == 1, a[n] == a[n-1]^4 + a[n-2]^4}, a, {n, 1, 8}] (* Vaclav Kotesovec, Dec 18 2014 *)
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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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EXTENSIONS
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STATUS
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approved
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