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 A116259 #2 Mar 30 2012 17:40:40 %S A116259 7282817,8171727,4550754022124826466,5449245977875173532, %T A116259 8176518705147900805,8951999555715882882349355522888, %U A116259 9861090464806791973258446431979 %N A116259 n times n+3 gives the concatenation of two numbers m and m-4. %e A116259 8171727 * 8171730 = 6677714//6677710, where // denotes %e A116259 concatenation. %Y A116259 Cf. A116128, A116253, A116260, A116274. %K A116259 nonn,base %O A116259 1,1 %A A116259 _Giovanni Resta_, Feb 06 2006