n = 25 (slider from 2 to 400, step 1)
p = 0.4 (slider from 0 to 1, step 0.01)
q: 1 - p
f(x) = exp((-(x - p)^(2)) / (2 * p * q / n)) / sqrt(2 * 3.141592653589793)
a = BarChart((-0.5) / n, 1 + 0.5 / n, Sequence[sqrt(n * p * q) * Binomial[n, k] * p^(k) * q^(n - k), k, 0, n])