%I A059870
%S A059870 2,3,5,6,7,8,10,11,15,17,18,20
%N A059870 Numbers n such that there exist no palindromic octagonal numbers of length 
               n.
%H A059870 P. De Geest, <a href="http://www.worldofnumbers.com/octa.htm">Palindromic 
               octagonals</a>
%Y A059870 Cf. A034822, A034307, A059868, A059869, A000567, A057106, A057107.
%Y A059870 Sequence in context: A084116 A137620 A028765 this_sequence A145353 A013936 
               A076437
%Y A059870 Adjacent sequences: A059867 A059868 A059869 this_sequence A059871 A059872 
               A059873
%K A059870 nonn,base,hard
%O A059870 1,1
%A A059870 Patrick De Geest (pdg(AT)worldofnumbers.com), Feb 15 2000.