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A346402
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Decimal expansion of Sum_{k>=1} A089723(k)/2^k.
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0
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1, 0, 6, 8, 3, 8, 9, 9, 3, 0, 0, 7, 8, 4, 1, 2, 3, 2, 0, 0, 2, 0, 8, 4, 7, 6, 5, 9, 0, 1, 7, 5, 8, 2, 3, 8, 2, 2, 4, 7, 2, 8, 9, 6, 0, 8, 6, 5, 5, 2, 8, 0, 7, 2, 1, 4, 9, 7, 8, 0, 7, 0, 7, 6, 0, 3, 1, 5, 3, 1, 6, 7, 9, 1, 8, 6, 4, 7, 6, 0, 7, 0, 5, 7, 4, 4, 1, 9, 7, 3, 0, 9, 2, 6, 3, 9, 3, 7, 8, 6
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OFFSET
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1,3
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COMMENTS
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This constant is irrational (Golomb, 1973).
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LINKS
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EXAMPLE
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1.06838993007841232002084765901758238224728960865528...
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MATHEMATICA
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f[n_] := DivisorSigma[0, GCD @@ FactorInteger[n][[;; , 2]]]; RealDigits[Sum[f[n]/2^n, {n, 1, 1000}], 10, 100][[1]]
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PROG
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(PARI) 1/2 + suminf(k=2, numdiv(gcd(factor(k)[, 2]))/2^k) \\ Michel Marcus, Jul 16 2021
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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