%I A020623
%S A020623 2,7,13,19,23,43,59,97
%N A020623 Smallest nonempty set S containing prime divisors of 9k+1 for each k 
               in S.
%Y A020623 Sequence in context: A156007 A067774 A063637 this_sequence A109346 A138646 
               A118755
%Y A020623 Adjacent sequences: A020620 A020621 A020622 this_sequence A020624 A020625 
               A020626
%K A020623 nonn,fini,full
%O A020623 1,1
%A A020623 David W. Wilson (davidwwilson(AT)comcast.net)