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A117871
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Decimal expansion of Sum_{i>=1} 1/A092143(i).
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5
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1, 6, 9, 1, 7, 9, 9, 2, 0, 9, 8, 2, 1, 7, 1, 2, 3, 5, 1, 3, 3, 9, 2, 6, 1, 8, 0, 6, 7, 8, 7, 6, 3, 1, 8, 6, 9, 8, 2, 3, 6, 9, 3, 7, 6, 2, 9, 2, 5, 8, 1, 9, 1, 3, 4, 5, 5, 6, 9, 5, 2, 0, 1, 4, 3, 4, 9, 2, 5, 7, 2, 0, 9, 1, 1, 5, 8, 3, 4, 5, 7, 1, 3, 0, 3, 9, 8, 3, 5, 9, 7, 3, 2, 5, 0, 1, 7, 7, 8, 0, 0, 2, 5, 3, 9
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OFFSET
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1,2
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COMMENTS
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It follows from the Mingarelli reference that this number is irrational.
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LINKS
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EXAMPLE
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1.6917992098217123513392618067876318698236937629258191345569...
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MAPLE
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Digits := 60 : A092143 := proc(n) option remember ; local dvs ; if n = 1 then 1 ; else dvs := numtheory[divisors](n) ; A092143(n-1)*mul(i, i=dvs) ; fi ; end: A129635 := proc(isum) a := 0.0 ; for i from 1 to isum do a := a+1.0/A092143(i) ; print(evalf(a)) ; od ; RETURN(a) ; end: A129635(200) ; # R. J. Mathar, Sep 02 2007
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MATHEMATICA
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digits = 105; A092143[m_] := For[n = k = 1, k <= m, k++, Do[n = n*d, {d, Divisors[k]}]; If[k == m, Return[n]]] ; rd[j_] := rd[j] = RealDigits[ N[ Sum[ 1/A092143[m], {m, 1, 2^j}], digits]][[1]]; rd[j = 4]; While[ rd[j] != rd[j - 1], j++]; rd[j] (* Jean-François Alcover, Oct 30 2012 *)
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CROSSREFS
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KEYWORD
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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