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 A181473 #7 Jun 15 2016 07:17:22 %S A181473 1,2,4,6,3,9,3,8,1,5,6,9,5,7,3,6,7,2,4,2,6,9,3,7,8,1,8,4,3,9,5,7,8,6, %T A181473 6,2,1,3,9,4,8,1,5,6,3,5,7,9,2,4,9,6,1,2,7,4,2,6,3,8,4,3,9,1,5,2,1,3, %U A181473 3,6,4,8,1,5,6,9,3,5,7,5,7,3,9,4,5,1,2,4,2,6,6,8,1,5,3,9,6,9,7,8,6,6,2,4,8 %N A181473 Digital root of EKG sequence. %e A181473 Digital root of the number 11 is 2 %Y A181473 Cf. A010888, A064413. %K A181473 nonn,easy,base %O A181473 1,2 %A A181473 _Parthasarathy Nambi_, Oct 22 2010