This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A083149 #10 Aug 11 2024 14:41:34 %S A083149 3,6,222,444,888,21312,42624,468864,40322304,80644608,802494494208, %T A083149 213525880454088525312,213525880454088738837880454088525312 %N A083149 a(1) = 3, a(n) = smallest nontrivial palindromic multiple of a(n-1). a(n) is not equal to a(n-1) or a concatenation of a(n-1) with itself. %C A083149 Multiplier for a(12) is larger than 2000000000. %H A083149 P. De Geest, <a href="https://www.worldofnumbers.com/em36.htm">WONplate 36</a> %Y A083149 Cf. A083150, A068665, A083147, A083151, A083153, A083155. %K A083149 nonn,base,more %O A083149 1,1 %A A083149 _Amarnath Murthy_ and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Apr 25 2003 %E A083149 More terms from _Patrick De Geest_, Jun 05 2003 %E A083149 a(13) from _Giovanni Resta_, Sep 22 2019