And I should have mentioned "experimental mathematics", which is really different! This term can be interpreted in weak and strong ways; the former, in which experiments are a preliminary to proof, is normal, but the latter, in which massive computer-generated experimental results are accepted as a substitute for proof when proof seems unlikely, is different. The key point is that most true theorems that we can understand have no proofs that we can understand, a fact that can itself be proved (at least if if you use length of the text as a proxy for whether we can understand it).