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 A040164 #10 Oct 10 2019 00:48:55 %S A040164 0,0,0,0,0,2,6,8,1,7,2,4,3,1,3,2,4,5,1,6,4,2,5,1,2,0,2,6,8,2,6,0,6,8, %T A040164 8,0,6,2,6,2,8,0,0,2,6,8,1,1,5,7,1,7,1,1,5,1,7,1,5,1,1,1,4,2,0,4,2,4, %U A040164 4,6,0,6,4,0,6,0,6,4,3,5,5,3,3,1,5,1,5,3,3,1,3,5,3,3,5,2,4,4,2,4,2,2,2,4,4 %N A040164 |First digit - last digit| for n-th prime. %F A040164 a(n) = A040163(A000040(n)). - _Michel Marcus_, Sep 27 2013 %o A040164 (PARI) a(n) = my(pn = prime(n), digs = digits(pn)); abs(digs[1] - digs[#digs]); \\ _Michel Marcus_, Sep 27 2013 %Y A040164 Cf. A000040, A040163. %K A040164 nonn,base,easy %O A040164 1,6 %A A040164 _Felice Russo_ %E A040164 Extended (and corrected) by _Patrick De Geest_, Jun 15 1999