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27 votes
4 answers
2k views

Do Abel summation and zeta summation always coincide?

This is a more focused version of Summation methods for divergent series. Let $a_n$ be a sequence of real numbers such that $\lim_{x \to 1^{-}} > \sum a_n x^n$ and $\lim_{s \to 0^{+}} > \...
David E Speyer's user avatar
13 votes
1 answer
782 views

Cesaro(?)/Euler(?) - summation of the $s(p)=\sum_{k=0}^\infty (-1)^{H(k)} (1+k)^p$ for $p=1,2,3,...$ (where $H(k)$ is the Hamming-weight)

In another thread (in MO) there was a question about a series where the signs at the terms alternate with the "Hamming-weight", that means according to the number of bits in the binary representation ...
Gottfried Helms's user avatar
9 votes
2 answers
2k views

Divergence of Dirichlet series

Suppose $s$ is a complex number with $\Re(s) \in (0,1]$ and $\{a_n\}$ is a complex sequence converging to $a \neq 0$. Must the Dirichlet series $$\sum_{n=1}^\infty\frac{a_n}{n^s}$$ diverge? I asked ...
Richard Hevener's user avatar
4 votes
1 answer
195 views

Reference request: Rigorously solving ODEs using divergent asymptotic series

In my research I have come across a divergent asymptotic series $\sum_{n =0}^\infty a_n f_n(x)$ that formally solves a certain fairly simple nonlinear second-order ODE but does not seem to correspond ...
tmh's user avatar
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