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 A082780 #8 Dec 05 2013 19:56:13 %S A082780 5,55,5005,505505,5005005005,50055055055005,50005050055005050005, %T A082780 5000005005005005005005000005,50000050055050055055055005055005000005 %N A082780 a(1) = 5, a(n) = smallest palindromic multiple of a(n-1) obtained by inserting digits anywhere in a(n-1). %Y A082780 Cf. A082776, A082777, A082778, A082779, A082781, A082782, A082783. %K A082780 base,more,nonn %O A082780 1,1 %A A082780 _Amarnath Murthy_, Apr 19 2003 %E A082780 Corrected by _Ray Chandler_, Oct 13 2003 %E A082780 a(8)-a(9) from _Sean A. Irvine_, Apr 19 2010