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 A116271 #2 Mar 30 2012 17:40:40 %S A116271 4,8600,9422,35440,64552,73643,4851411,5148581,8784945,726216462984, %T A116271 753613723258,791909893641,819307153915,3654754464602947512, %U A116271 4527063717215234298,5472936282784765694,6345245535397052480 %N A116271 n times n+9 gives the concatenation of two numbers m and m-3. %e A116271 8784945 * 8784954 = 7717533//7717530, where // denotes %e A116271 concatenation. %Y A116271 Cf. A116140, A116264, A116270, A116278. %K A116271 nonn,base %O A116271 1,1 %A A116271 _Giovanni Resta_, Feb 06 2006