%I A115657
%S A115657 1,5,22,210,287,782,1001,2882,7740,15251,77180,565187,720027,781565,
%T A115657 7081807,7451547,26811862,54177145,206489067,246214610,760984602,
%U A115657 1050660501,1085885801,1528888251,2642326276,2911771192,6726232462
%N A115657 Both n and the reverse of n are pentagonal numbers (A000326).
%e A115657 565187=P(614) and 781565=P(722), where P(k)=k(3k-1)/2 is the k-th pentagonal 
               number.
%Y A115657 Cf. A000326, A061455, A061457.
%Y A115657 Sequence in context: A129437 A048252 A066866 this_sequence A066865 A005632 
               A002069
%Y A115657 Adjacent sequences: A115654 A115655 A115656 this_sequence A115658 A115659 
               A115660
%K A115657 base,nonn
%O A115657 1,2
%A A115657 Giovanni Resta (g.resta(AT)iit.cnr.it), Jan 28 2006