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In number theory, an aurifeuillean factorization, named after Léon-François-Antoine Aurifeuille, is a special type of algebraic factorization that comes from non-trivial factorizations of cyclotomic polynomials over the integers. Although cyclotomic polynomials themselves are irreducible over the integers, when restricted to particular integer values they may have an algebraic factorization, as in the examples below. == Examples == * Numbers of the form have the following aurifeuillean factorization: :: * Numbers of the form or , where with square-free , have aurifeuillean factorization if and only if one of the following conditions holds: * * and * * and : Thus, when with square-free , and is congruent to mod , then if is congruent to 1 mod 4, have aurifeuillean factorization, otherwise, have aurifeuillean factorization. : When the number is of a particular form (the exact expression varies with the base), Aurifeuillian factorization may be used, which gives a product of two or three numbers. The following equations give Aurifeuillian factors for the Cunningham project bases as a product of ''F'', ''L'' and ''M'':〔(【引用サイトリンク】url=http://homes.cerias.purdue.edu/~ssw/cun/pmain1211 ) At the end of tables 2LM, 3+, 5-, 7+, 10+, 11+ and 12+ are formulae detailing the Aurifeuillian factorisations.〕 : If we let ''L'' = ''A'' - ''B'', ''M'' = ''A'' + ''B'', the Aurifeuillian factorizations for ''b''''n'' ± 1 with the base 2 ≤ ''b'' ≤ 24 (perfect powers excluded, since a power of ''b''''n'' is also a power of ''b'') are: : (Number = ''F'' * (''A'' - ''B'') * (''A'' + ''B'') = ''F'' * ''L'' * ''M'') : : (See 〔(List of Aurifeuillean factorization )〕 for more information (square-free bases up to 199)) : In fact, ''L'' * ''M'' = , where with square-free , and ''n'' = ''t'' if ''t'' is congruent to 1 mod 4. Otherwise, ''n'' = 2''t''. * Numbers of the form have the following aurifeuillean factorization: :: * Lucas number have the following aurifeuillean factorization: :: : where is the th Lucas number, is the th Fibonacci number. 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Aurifeuillean factorization」の詳細全文を読む スポンサード リンク
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