A = (2, 2)
B = (15, 2)
a = Segment(A, B)
n = 10 (slider from 1 to 19, step 1)
liste1 = Sequence(A + i * (B - A) / n, i, 0.0, n)
liste2 = Sequence(Text["A_" + (i)], i, 0.0, n)
C = (2.6876221498371335, 0.4504885993485344)
liste4 = Sequence(Text["A_{" + (i) + "}", Element[liste1, i] - (0.0, 0.3)], i, 0.0, n + 1.0)