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 A072725 #3 Mar 30 2012 18:51:38 %S A072725 1,4,823 %N A072725 Integers which are exactly the concatenation of the first m numbers (A007908) divided by their sum (A000217 = m*(m+1)/2). %C A072725 A probability argument suggests that this sequence may be finite. %e A072725 a(1) = 1/1 =1; a(2) = 12/(1+2) = 4; a(3) = 12345/(1+2+3+4+5). %Y A072725 Cf. A067116, A072723, A072724. %K A072725 base,nonn,bref %O A072725 1,2 %A A072725 _Henry Bottomley_, Jul 06 2002