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 A055158 #4 Mar 30 2012 18:51:25 %S A055158 954,7641,98754210,987654321,9876543210 %N A055158 n has distinct digits in descending order and n=a+b where a has the digits of n in another order and b has the digits of n in ascending order (perhaps with leading zeros). %D A055158 Denis Borris, Ken Duisenberg's Puzzle of the Week, April 20, 2000 %H A055158 <a href="http://www.ecst.csuchico.edu/~kend/potw/archive/000420sol.html">Source</a> %F A055158 a(n)= A055157(n)+A055159(n) %e A055158 954=495+459 %Y A055158 Cf. A055161. %K A055158 fini,full,base,nonn %O A055158 0,1 %A A055158 _Henry Bottomley_, Apr 27 2000