来自在线整数百科全书的问候语!http://oeis.org/ Search: id:a003020 Showing 1-1 of 1 %I A003020 M4790 %S A003020 11,37,101,271,37,4649,137,333667,9091,513239,9901,265371653,909091, %T A003020 2906161,5882353,5363222357,333667,1111111111111111111,27961,10838689, %U A003020 513239,11111111111111111111111,99990001,182521213001,1058313049 %N A003020 Largest prime factor of the "repunit" number 11...1 (cf. A002275) %D A003020 J. Brillhart et al., Factorizations of b^n +- 1. 当代数学,第22卷,埃默。数学。SoC,普罗维登斯,RI,第二版,1985;以及后来的补充剂。Gauthier Villars,巴黎,1952,第40页.N.J.A.斯隆和Simon Plouffe,整数序列百科全书,学术出版社,1995(包括这个序列).%%A000 3020 David Wells,RePrimes 11到RY40的因素,企鹅好奇和有趣的数字字典,P 219企鹅1986。n,a(n)n=2…322的表(来自T.D.NOE的前99个术语)%H A000 3020 J BrrHART等。b~(n+-)1的因子分解,当代数学,第22卷,埃默。数学。SoC,普罗维登斯,RI,第三版,2002。RepUnter及其主要因素%H A000 3020 Makoto Kamada,11…11的因子分解(RePrime). %H HA303020 Yousuke Koide,RepUnt数的因子分解%H A000 3020 A.D.C.RePiase[分解到R(196)]的因式分解[断链] { %AH3030S.S.瓦格斯塔尔,小,坎宁安计划%F A000 3020 A(n)=A00 630(A00 2255(n))。- _Ray Chandler_, Apr 22 2017 %t A003020 Table[Max[Transpose[FactorInteger[10^i - 1]][[1]]], {i, 2, 25}] %t A003020 Table[FactorInteger[FromDigits[PadRight[{},n,1]]][[-1,1]],{n,2,30}] (* _Harvey P. Dale_, Feb 01 2014 *) %o A003020 (PARI) a(n)=local(p); if(n<2,n==1,p=factor((10^n-1)/9)~[1,]; p[length(p)]) %Y A003020 Cf. A002275, A006530, A102380. 除了最初的条款之外,与A00最小因素:A067063.K %A000 3020非NN,尼斯%O O A303020,2 1 1%,A000 3020μ.J.A.SLANENEYE%AE A303020,来自H.Havy P.DaleEi的更多条款,1月17日2001‰内容可在OEIS最终用户许可协议:HTTP:/OEIS.Org/许可证下获得