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 A116266 #4 Feb 20 2019 15:03:44 %S A116266 7,7311,8990,32523,67476,76567,4891729,5108270,8528093,71588335, %T A116266 98999900,399659933006,600340066993,723627738226,877712329767, %U A116266 998999999000,3485626998113,3787100274613,6212899725386,6514373001886 %N A116266 n times n+2 gives the concatenation of two numbers m and m-3. %e A116266 98999900 * 98999902 = 98009803//98009800, where // denotes %e A116266 concatenation. %Y A116266 Cf. A115431, A116252, A116265, A116267, A116273. %K A116266 nonn,base %O A116266 1,1 %A A116266 _Giovanni Resta_, Feb 06 2006