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A113533
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Ascending descending base exponent transform of the infinite Fibonacci word (A003842).
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2
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1, 3, 6, 5, 7, 12, 10, 15, 14, 14, 23, 16, 20, 27, 21, 30, 27, 25, 40, 28, 37, 38, 32, 49, 36, 40, 53, 39, 54, 49, 43, 68, 45, 55, 66, 50, 71, 60, 56, 83, 57, 74, 75, 61, 92, 67, 73, 94, 68, 93, 84, 72, 113, 75, 94, 101, 79, 116, 89, 91, 122, 86, 115, 108, 90
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OFFSET
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1,2
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COMMENTS
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The infinite Fibonacci word b(n) is the fixed point of the morphism 1->12, 2->1, starting from b(1) = 2. This transform a(n) of that sequence b(n) satisfies n <= a(n) <= 4*n, but that is not a tight bound.
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LINKS
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FORMULA
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EXAMPLE
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a(3) = 1^1 + 2^2 + 1^1 = 6.
a(4) = 1^1 + 2^1 + 1^2 + 1^1 = 5.
a(5) = 1^2 + 2^1 + 1^1 + 1^2 + 2^1 = 7.
a(6) = 1^1 + 2^2 + 1^1 + 1^1 + 2^2 + 1^1 = 12.
a(7) = 1^2 + 2^1 + 1^2 + 1^1 + 2^1 + 1^2 + 2^1 = 10.
a(8) = 1^1 + 2^2 + 1^1 + 1^2 + 2^1 + 1^1 + 2^2 + 1^1 = 15.
a(9) = 1^1 + 2^1 + 1^2 + 1^1 + 2^2 + 1^1 + 2^1 + 1^2 + 1^1 = 14.
a(10) = 1^2 + 2^1 + 1^1 + 1^2 + 2^1 + 1^2 + 2^1 + 1^1 + 1^2 + 2^1 = 14.
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MATHEMATICA
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A003842[n_] := n + 1 - Floor[((1 + Sqrt[5])/2)*Floor[2*(n + 1)/(1 + Sqrt[5])]]; Table[Sum[A003842[k]^(A003842[n - k + 1]), {k, 1, n}], {n, 1, 50}] (* G. C. Greubel, May 18 2017 *)
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CROSSREFS
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Cf. A003842, A005408, A087316, A113122, A113153, A113154, A113208, A113231, A113257, A113258, A113271, A113320, A113336, A113498.
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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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