
{"id":3366,"date":"2008-03-04T14:30:00","date_gmt":"2008-03-04T05:30:00","guid":{"rendered":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/?p=3366"},"modified":"2021-08-12T11:53:28","modified_gmt":"2021-08-12T02:53:28","slug":"eulerinformation","status":"publish","type":"post","link":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/2008\/03\/04\/eulerinformation\/","title":{"rendered":"EulerInformation"},"content":{"rendered":"<p> Describe EulerInformation here <\/p>\n<p> The totient function , also called Euler&#8217;s totient function, is defined as the number of positive integers  that are relatively prime to (i.e., do not contain any factor in common with) , where 1 is counted as being relatively prime to all numbers. Since a number less than or equal to and relatively prime to a given number is called a totative, the totient function  can be simply defined as the number of totatives of . For example, there are eight totatives of 24 (1, 5, 7, 11, 13, 17, 19, and 23), so . The totient function is implemented in Mathematica as EulerPhi[n]. <\/p>\n<p> is always even for . By convention, , although Mathematica defines EulerPhi[0] equal to 0 for consistency with its FactorInteger[0] command. The first few values of  for , 2, &#x2026; are 1, 1, 2, 2, 4, 2, 6, 4, 6, 4, 10, &#x2026; (Sloane&#8217;s A000010). The totient function is given by the M&amp;ouml;bius transform of 1, 2, 3, 4, &#x2026; (Sloane and Plouffe 1995, p. 22).  is plotted above for small . <\/p>\n<p> For a prime , <\/p>\n<p> (1) <\/p>\n<p> since all numbers less than  are relatively prime to . If  is a power of a prime, then the numbers that have a common factor with  are the multiples of : , , &#x2026;, . There are  of these multiples, so the number of factors relatively prime to  is <\/p>\n<p> (2) <\/p>\n<p> Now take a general  divisible by . Let  be the number of positive integers  not divisible by . As before, , , &#x2026;,  have common factors, so <\/p>\n<p> (3) <\/p>\n<p> Now let  be some other prime dividing . The integers divisible by  are , , &#x2026;, . But these duplicate , , &#x2026;, . So the number of terms that must be subtracted from  to obtain  is <\/p>\n<p> (4) <\/p>\n<p> and <\/p>\n<p> (5) (6) (7) <\/p>\n<p> By induction, the general case is then <\/p>\n<p> (8) <\/p>\n<p> An interesting identity relating  to  is given by <\/p>\n<p> (9) <\/p>\n<p> (A. Olofsson, pers. comm., Dec. 30, 2004). <\/p>\n<p> Another identity relates the divisors  of  to  via <\/p>\n<p> (10) <\/p>\n","protected":false},"excerpt":{"rendered":"<p>Describe EulerInformation here The totient function , also called Euler&#8217;s totient function, is defined as the number of positive integers that are relatively prime to (i.e., do not contain any factor in common with) , where 1 is counted as being relatively prime to all numbers. Since a number less than or equal to and &#8230; <a title=\"EulerInformation\" class=\"read-more\" href=\"https:\/\/mathematicians.korea.ac.kr\/ywkim\/2008\/03\/04\/eulerinformation\/\" aria-label=\"EulerInformation\uc5d0 \ub300\ud574 \ub354 \uc790\uc138\ud788 \uc54c\uc544\ubcf4\uc138\uc694\">\ub354 \uc77d\uae30<\/a><\/p>\n","protected":false},"author":7,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-3366","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"distributor_meta":false,"distributor_terms":false,"distributor_media":false,"distributor_original_site_name":"\uae40\uc601\uc6b1","distributor_original_site_url":"https:\/\/mathematicians.korea.ac.kr\/ywkim","push-errors":false,"_links":{"self":[{"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/posts\/3366","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/comments?post=3366"}],"version-history":[{"count":1,"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/posts\/3366\/revisions"}],"predecessor-version":[{"id":3367,"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/posts\/3366\/revisions\/3367"}],"wp:attachment":[{"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/media?parent=3366"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/categories?post=3366"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/tags?post=3366"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}