%I A114950
%S A114950 1,1,2,83525,48670514501156640914,
%T A114950 5611303368570568119463158581109807779153712597124269146443734128560476495542441
%N A114950 A quartic quadratic recurrence.
%C A114950 a(6) has 315 digits. This sequence is related to: A112969 "quartic Fibonacci
sequence" a(1) = a(2) = 1; for n>2: a(n) = a(n-1)^4 + a(n-2)^4, which
is the quartic (or biquadratic) analogue of the Fibonacci sequence
similarly to A000283 being the quadratic analogue of the Fibonacci
sequence. Primes in this sequence include a(n) for n = 2, 3. Semiprimes
in this sequence include a(n) for n = 5.
%F A114950 a(0) = a(1) = 1, for n>1 a(n) = a(n-2)^4 + a(n-1)^2.
%e A114950 a(2) = a(1)^4 + a(0)^2 = 1^4 + 1^2 = 2.
%e A114950 a(3) = a(2)^4 + a(1)^2 = 2^4 + 1^2 = 17.
%e A114950 a(4) = a(3)^4 + a(2)^2 = 17^4 + 2^2 = 83525.
%e A114950 a(5) = a(4)^4 + a(3)^2 = 83525^4 + 17^2 = 48670514501156640914.
%Y A114950 Cf. A000283, A112969, A114793.
%Y A114950 Sequence in context: A100266 A071067 A060069 this_sequence A003840 A122540
A167518
%Y A114950 Adjacent sequences: A114947 A114948 A114949 this_sequence A114951 A114952
A114953
%K A114950 easy,nonn
%O A114950 0,3
%A A114950 Jonathan Vos Post (jvospost3(AT)gmail.com), Feb 21 2006
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