- Erdős–Borwein constant
The Erdős–Borwein
constant is the sum of the reciprocals of the Mersenne numbers. It is named afterPaul Erdős andPeter Borwein .By definition it is:
:
It can be proven that the following forms are equivalent to the former:
:
:
:
:
where σ0("n") = "d"("n") is the
divisor function , amultiplicative function that equals the number of positivedivisor s of the number "n". To prove the equivalence of these sums, note that they all take the form ofLambert series and can thus be resummed as such.Erdős in
1948 showed that the constant "E" is anirrational number .External links
*
* Sloan Sequence [http://www.research.att.com/~njas/sequences/A065442 A065442] in OEIS
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