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 A083155 #11 Aug 11 2024 14:41:34 %S A083155 9,171,1881,171171,1882881,306909603,11355655311,1033364633301, %T A083155 1034397997934301,10241574577547514201,10231343244544544234313201, %U A083155 112544775689989986577445211,1023144555797698967975554413201,102221350448336861989168633844053122201,11233003103852144358833233885344125830130033211 %N A083155 a(1) = 9, 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 A083155 Variant of A068668. [From _R. J. Mathar_, Dec 15 2008] %H A083155 P. De Geest, <a href="https://www.worldofnumbers.com/em36.htm">WONplate 36</a> %Y A083155 Cf. A083156, A068668, A083153, A083151, A083149, A083147. %K A083155 base,nonn %O A083155 1,1 %A A083155 _Amarnath Murthy_ and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Apr 25 2003 %E A083155 Corrected and extended by _Patrick De Geest_, Jun 05 2003 %E A083155 a(14)-a(15) from _Giovanni Resta_, Sep 25 2019