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 A116280 #2 Mar 30 2012 17:40:40 %S A116280 6,77,80918,91808,326509,475024,524974,673489,4323776,4767131,5232867, %T A116280 5676222,4083911140,4975000249,5024999749,5916088858,9503960495, %U A116280 9604950395,4186904462791,4313465946774,5686534053224,5813095537207 %N A116280 n times n+3 gives the concatenation of two numbers m and m-1. %Y A116280 Cf. A116149, A116274, A116279, A116281, A116287. %K A116280 nonn,base %O A116280 1,1 %A A116280 _Giovanni Resta_, Feb 06 2006