Using Python tricks to find Minimum Coin Change (Amazon Interview)
Welcome to Code Review! Your code looks fine, and is fairly easy to follow. A few points to note though:
Since your initial if-elif clauses are returning values immediately, no need to wrap an else (and even elif) there:
if n in coins:
    known_results[n] = 1
    return 1
if known_results[n] &gt; 0:     
    return known_results[n] 
for i in [c for c in coins if c&lt;=n]:
    .
    .

is achieving the same thing.
In python, multiple assignments can be done in a single statement:
known_results[n] = min_coins = count

As an aside, you can make use of type hinting to make the values and parameters more understandable. If I was only reading through the function definition, I'd have no idea what known_results was supposed to be.