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A343818
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a(n) is the least number k such that k and k+1 both have n Fermi-Dirac factors (A064547).
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2
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OFFSET
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1,1
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COMMENTS
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Since the number of infinitary divisors of k is A037445(k) = 2^A064547(k), a(n) is also the least number k such that k and k+1 both have 2^n infinitary divisors.
a(9) > 2*10^11, if it exists.
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LINKS
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EXAMPLE
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MATHEMATICA
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fd[1] = 0; fd[n_] := Plus @@ DigitCount[FactorInteger[n][[;; , 2]], 2, 1]; seq[m_] := Module[{s = Table[0, {m}], c = 0, n = 1, fd1, fd2}, fd1=fd[n]; While[c < m, fd2 = fd[++n]; If[fd1 == fd2 && fd1 <= m && s[[fd1]] == 0, s[[fd1]] = n-1; c++]; fd1=fd2]; s]; seq[5]
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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STATUS
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approved
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