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 A224536 #5 Apr 22 2013 00:12:06 %S A224536 4,8,2,8,3,2,2,8,2,6,4,5,1,6,1,2,2,4,1,8,0,4,3,5,1,2,2,6,2,4,1,7,0,5, %T A224536 2,2,1,5,2,6,2,5,1,6,2,1,3,5,1,5,2,3,2,4,2,1,2,8,1,5,2,6,0,6,3,2,1,6, %U A224536 1,4,2,4,1,6,1,2,2,6,1,4,1,4,4,6,0,3,1 %N A224536 Number of ways a digit can be appended or prepended to n and form a unique prime. %C A224536 See A224953 for the main entry. The only difference is a(1) = 8, when two copies of 11 are produced. %K A224536 nonn,base %O A224536 0,1 %A A224536 _T. D. Noe_, Apr 21 2013