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A374540
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a(1) = 0; for n >= 2, a(n) is the number of iterations needed for the map x -> x/A000005(x) to reach a least integer, when starting from x = A033950(n).
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1
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0, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 3, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
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OFFSET
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1,3
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COMMENTS
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The refactorability "depth" for refactorable numbers. Numbers from A159973 have the refactorability "depth" 0. Records reached for A033950(A360806(n)), i.e. the growth of the sequence is very slow.
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LINKS
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EXAMPLE
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MATHEMATICA
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f[n_] := Module[{v = NestWhileList[# / DivisorSigma[0, #] &, n, IntegerQ[#] && # > 1 &], len}, len = Length[v]; If[IntegerQ[v[[2]]], If[v[[-1]] == 1, len - 1, len - 2], Nothing]]; f[1] = 0; Array[f, 1200] (* Amiram Eldar, Jul 11 2024 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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