%I A102380
%S A102380 1,11,3,37,11,101,41,271,3,7,11,13,37,239,4649,11,73,101,137,3,3,37,
%T A102380 333667,11,41,271,9091,21649,513239,3,7,11,13,37,101,9901,53,79,
%U A102380 265371653,11,239,4649,909091,3,31,37,41,271,2906161,11,17,73,101
%N A102380 Triangle read by rows in which row n lists prime factors (with multiplicity) 
               of (10^n - 1)/9.
%C A102380 See A003020 for other links and references.
%H A102380 T. D. Noe, <a href="b102380.txt">Rows n=1..100 of triangle, flattened</
               a> (derived from Yousuke Koide)
%H A102380 Makoto Kamada, <a href="http://homepage2.nifty.com/m_kamada/math/11111.htm">
               Factorizations of 11...11 (repunit)</a>.
%H A102380 Yousuke Koide, <a href="http://www.h4.dion.ne.jp/~rep/">Factorizations 
               of Repunit Numbers</a>
%e A102380 1; (11); (3) (37); (11) (101); (41) (271); (3) (7) (11) (13) (37); (239) 
               (4649); ...
%p A102380 [seq( ifactor((10^n-1)/9),n=1..20)];
%Y A102380 Cf. A002275, A067063, A003020.
%Y A102380 Sequence in context: A088653 A107598 A087100 this_sequence A147555 A157883 
               A038317
%Y A102380 Adjacent sequences: A102377 A102378 A102379 this_sequence A102381 A102382 
               A102383
%K A102380 nonn,tabf
%O A102380 1,2
%A A102380 N. J. A. Sloane (njas(AT)research.att.com), Nov 28 2006