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 A112969 a(n) = a(n-1)^4 + a(n-2)^4 for n > 2 with a(1) = a(2) = 1. 10
 1, 1, 2, 17, 83537, 48698490414981559682, 5624216052381164150697569400035392464306474190030694298257552124199835791859537 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS 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). LINKS Eric Weisstein's World of Mathematics, Quartic Equation. FORMULA a(n) ~ c^(4^n), where c = 1.0111288972169538887655499395580320278253918666919181401824606983217263409... . - Vaclav Kotesovec, Dec 18 2014 EXAMPLE 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. MATHEMATICA RecurrenceTable[{a ==1, a == 1, a[n] == a[n-1]^4 + a[n-2]^4}, a, {n, 1, 8}] (* Vaclav Kotesovec, Dec 18 2014 *) CROSSREFS Cf. A000045, A000283. Sequence in context: A163319 A269836 A114950 * A208208 A290189 A279883 Adjacent sequences:  A112966 A112967 A112968 * A112970 A112971 A112972 KEYWORD easy,nonn AUTHOR Jonathan Vos Post, Jan 02 2006 EXTENSIONS Name edited by Petros Hadjicostas, Nov 03 2019 STATUS approved

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Last modified September 19 02:22 EDT 2020. Contains 337175 sequences. (Running on oeis4.)