The cutoff for listing on the results page was 5.  Here are philosophers that got 2-4 mentions (N.B. we had to clean up mentions in different formats so these results may be imperfect).

Goodman: 4
Sextus Empiricus: 4
Brentano: 4
Bernard Williams: 4
Rand: 4
Ross: 4
Kuhn: 4
Beauvoir: 3
Reichenbach: 3
Habermas: 3
Ramsey: 3
Nozick: 3
Prior: 3
Meinong: 3
Parmenides: 3
Alston: 2
Jaspers: 2
Confucius: 2
Oakeshott: 2
Hare: 2
Hayek: 2
Broad: 2
Plotinus: 2
Nagarjuna: 2
Arendt: 2
G.A. Cohen: 2
Buber: 2
Mencius: 2
Berlin: 2
Evans: 2
Fichte: 2
Feyerabend: 2
Bentham: 2
McTaggart: 2
Protagoras: 2
Rosenzweig: 2