翻訳と辞書 Words near each other ・ feep ・ feeper ・ feeping creature ・ feeping creaturism ・ fel ・ femto- ・ fence ・ fencepost error ・ fepped out ・ feprom ・ fermat prime ・ ferranti f100-l ・ ferrite core memory ・ ferroelectric ram ・ ferroelectric random access memory ・ fetch ・ fetch-execute cycle ・ feynman, richard p. ・ ff ・ ffccc Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク fermat prime ： FOLDOC Fermat prime A {prime number} of the form 2^2^n + 1. Any prime number of the form 2^n+1 must be a Fermat prime. {Fermat} conjectured in a letter to someone or other that all numbers 2^2^n+1 are prime, having noticed that this is true for n=0,1,2,3,4. Euler proved that 641 is a factor of 2^2^5+1. Of course nowadays we would just ask a computer, but at the time it was an impressive achievement (and his proof is very elegant). No further Fermat primes are known; several have been factorised, and several more have been proved composite without finding explicit factorisations. Gauss proved that a regular N-sided {polygon} can be constructed with ruler and compasses if and only if N is a power of 2 times a product of distinct Fermat primes. (1995-04-10) スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.