where `F(x_1,\dots,x_ℓ)\in\mathbb{Q}[x_1,\dots,x_ℓ]`, `H_n^{(m)}(z)=\sum_{j=1}^n1/(j+z)^m`, and `s_1,\dots,s_k` are nonnegative integers with `s_1+\cdots+s_k\geq 2`, as a linear combination of multiple Hurwitz zeta functions and harmonic functions.
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