A variant of a statement by this man that adds positive integer coefficients is named after S. S. Pillai. Preda Mihailescu used cyclotomic polynomials to prove a conjecture named for this man, which asserts that the only nontrivial solutions are 2^3 (“two cubed”) and 3^2 (“three squared”). That conjecture by this man involves the Diophantine equation [read (-5[1])slowly]: “x to the a minus y to the b equals one.” Euler used constructs named for this mathematician to calculate the number of ways to (*) triangulate a convex n+2-gon. This man’s namesake number is proportional to 2n choose n, thus one can derive his namesake numbers by taking the central column of Pascal’s triangle. For 10 points, name this mathematician whose namesake numbers begin with 1, 1, 2, 5, and (0[1])14. ■END■