Geometrische Reihe

n = 7 (slider from 1 to 100, step 1)
a = 1 (slider from 0 to 3, step 0.1)
f(x) = If[0 ≤ x ≤ Infinity, 1 / x^(a)]
A = RectangleSum(f, 1, n + 1, n, 0)
l1 = Sequence((i, f(i)), i, 1, n)
l2 = Sequence((y(Sum[l1, i]), 0), i, 1, n + 1)
sumtext: "\sum_{k=1}^{" + (LaTeX[n]) + "}{\frac{1}{k^{" + (LaTeX[a]) + "}}}=" + (LaTeX[A]) + ""