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 A071885 #5 Nov 04 2013 12:21:57 %S A071885 38,70,117,198,368,210,558,1312,693,3920,2438,6900,17138,43792,105939, %T A071885 553150,862695,5466578,262720694,8088309190,155799611901, %U A071885 2918284055518,415202250061643,1166813484199476,224311803609338424 %N A071885 Trajectory of 38 under map x -> A002487(x)*A002487(x+1). %Y A071885 Cf. A002487, A071884, A071886, A071887. %K A071885 nonn %O A071885 0,1 %A A071885 _N. J. A. Sloane_ and _J. H. Conway_, Jun 10 2002