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A258215
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Number of steps from n to 0, where allowable steps are x -> [x/r] if x is in lower Wythoff sequence (A000201) and x -> [r*x] otherwise, where [ ] = floor and r = (1+sqrt(5))/2 = golden ratio.
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2
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0, 1, 3, 2, 4, 6, 3, 5, 5, 7, 9, 4, 6, 8, 6, 8, 8, 10, 12, 5, 7, 7, 9, 11, 7, 9, 11, 9, 11, 11, 13, 15, 6, 8, 10, 8, 10, 10, 12, 14, 8, 10, 10, 12, 14, 10, 12, 14, 12, 14, 14, 16, 18, 7, 9, 9, 11, 13, 9, 11, 13, 11, 13, 13, 15, 17, 9, 11, 13, 11, 13, 13, 15
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OFFSET
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0,3
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COMMENTS
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a(n) = number of edges from 0 to n in the tree at A258212.
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LINKS
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EXAMPLE
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35->21->12->7->11->6->3->1->0, so that a(35) = 8.
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MATHEMATICA
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r = GoldenRatio; w = Table[Floor[r*n], {n, 1, 1000}];
f[x_] := If[MemberQ[w, x], Floor[x/r], Floor[r*x]];
g[x_] := Drop[FixedPointList[f, x], -1];
Table[-1+ Length[g[n]], {n, 0, 100}]
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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