%I A048920
%S A048920 1,104,14725,2090804,296879401,42154784096,5985682462189,
%T A048920 849924754846700,120683329505769169,17136182865064375256,
%U A048920 2433217283509635517141,345499718075503179058724
%N A048920 Indices of heptagonal numbers (A000566) which are also 9-gonal.
%H A048920 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               NonagonalHeptagonalNumber.html">Link to a section of The World of 
               Mathematics.</a>
%Y A048920 Cf. A000566, A048919, A048921.
%Y A048920 Sequence in context: A004393 A164759 A015272 this_sequence A091539 A157874 
               A069172
%Y A048920 Adjacent sequences: A048917 A048918 A048919 this_sequence A048921 A048922 
               A048923
%K A048920 nonn
%O A048920 1,2
%A A048920 Eric Weisstein (eric(AT)weisstein.com)