Here http://integralsandseries.prophpbb.com/topic119.html
We came across the following harmonic sum
$$\tag{1} \sum_{k\geq 1}\frac{(-1)^{k-1}}{k^2}H_k^{(2)}$$
Note that we define
$$H_k^{(2)}=\sum_{n\geq 1}^k\frac{1}{n^2} $$
Also we have
$$\psi_1(k+1)= \zeta(2) -H_k^{(2)} $$
Any ideas how to evaluate (1) ?
Answer
A related problem. You can have the following identity
$$\sum_{k=1}^{\infty}(-1)^{k-1} \frac{H_k^{(2)}}{k^2} = \frac{37}{16}\zeta(4)+2\sum_{k=1}^{\infty}(-1)^k \frac{H_k}{k^3}\sim 0.7843781621 .$$
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