Back to Minimum overlap problem

n = 10
f(x) = 0for 0x < 1/5
f(x) = 0.427849980190994044for 1/5x < 2/5
f(x) = 0.537828535348129426for 2/5x < 3/5
f(x) = 0.663356982483178949for 3/5x < 4/5
f(x) = 0.870964501977697581for 4/5x ≤ 1
f(x) = f(2-x)for 1< x ≤ 2
Illustration
α(f) < 0.382427116707499603
 maximal for 1/5 ≤ |k| ≤ 4/5