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A062000
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a(n) = a(n-1)^2 - a(n-2)^2 with a(0) = 0, a(1) = 2.
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2
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OFFSET
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0,2
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LINKS
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FORMULA
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a(n) ~ c^(2^n), where c = 1.35388068260888709216374860554901303232201699191445590979673901150215855854... . - Vaclav Kotesovec, Dec 17 2014
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EXAMPLE
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a(3) = 4^2 - 2^2 = 12.
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MATHEMATICA
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RecurrenceTable[{a[0]==0, a[1]==2, a[n]==a[n-1]^2 - a[n-2]^2}, a, {n, 0, 10}] (* Vaclav Kotesovec, Dec 17 2014 *)
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PROG
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(PARI) { for (n=0, 12, if (n>1, a=a1^2 - a2^2; a2=a1; a1=a, if (n==0, a=a2=0, a=a1=2)); write("b062000.txt", n, " ", a) ) } \\ Harry J. Smith, Jul 29 2009
(SageMath)
if (n<2): return 2*n
else: return a(n-1)^2 - a(n-2)^2
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CROSSREFS
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KEYWORD
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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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