His namesake numbers, used in pseudo-random number generators, take the form 2 to the 2-to-the-nth p
His namesake numbers, used in pseudo-random number generators, take the form 2 to the 2-to-the-nth power plus 1.  A result by this man, generalized by Carmichael's theorem and Euler's totient theorem, states that A raised to the power p, where p is prime, is congruent to A, modulo p. He's not Leibniz, but Newton acknowledge this man's earlier method of differentiation, and this man noted in the margin of a copy of Diophantus' Arithmetica that no integer n greater than 2 solves the equation "a to the n plus b to the n equals c to the n", which Andrew Wiles proved in 1993. For 10 points, name this 17th-century French mathematician known for his "little" and "last" theorems.
His namesake numbers, used in pseudo-random number generators, take the form 2 to the 2-to-the-nth power plus 1.  
Pierre de Fermat