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 A025509 #5 Mar 30 2012 18:35:25 %S A025509 3,2,4,3,2,19,18,17,16,41,149,148,147,146,145,225,224,223,222,221,220, %T A025509 219,218,217,377,376,375,577,576,575,574,573,572,571,570,569,568,567, %U A025509 566,565,564,563,7697,7696,7695,7694,7693,7692,7691,7690,7689,7688,7687,7686 %N A025509 Least k>1 such that reverse of first n terms of A006928 repeats beginning at k-th term. %K A025509 nonn %O A025509 1,1 %A A025509 _David W. Wilson_