This little brochure is aimed at a much broader part of the mathematical community than previously published books on experimental mathematics like Experimental Mathematics in Action or Mathematics by Experiment: Plausible Reasoning in the 21st Century written by the first author. It can be used at student seminars as a starting point of independent research based on the heavy use of computers. Attention is given to things connected with pi, to recognition of important constants from their decimal expansion or to the zeta function. Results are presented without proofs and with a maximal effort to make them understandable. The book also contains parts denoted ‘Explorations’. They give the reader a chance to try to apply the learned material on some additional problems. It is a pleasant and readable book for any working mathematician who wants to know something more about the use of computers for generating hypotheses on relations among known and less known special numbers.