The polynomial moments of the weight w (first half of Proposition 2.2) #
∫₀^∞ y^{2e} w(y) dy = μ(t^e) = (-1)^e B_{2e+2} (2e+3)(2e+4)(2e+5) / 24, from the Gamma
integral, term-wise integration of the series defining w, and Euler's formula
ζ(2k) = (-1)^{k+1} 2^{2k-1} π^{2k} B_{2k} / (2k)! (hasSum_zeta_nat in Mathlib).
theorem
Zeta5Irrational.integrableOn_pow_mul_exp_neg_mul
(m : ℕ)
{r : ℝ}
(hr : 0 < r)
:
MeasureTheory.IntegrableOn (fun (y : ℝ) => y ^ m * Real.exp (-(r * y))) (Set.Ioi 0) MeasureTheory.volume