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 A232191 #10 Nov 20 2013 20:01:08 %S A232191 3,2,1,2,3,4,3,2,1,2,3,4,5,6,7,8,9,8,7,6,5,4,3,2,3,4,5,6,5,4,3,4,5,6, %T A232191 7,8,9,8,7,8,9,8,7,6,5,4,3,2,3,4,5,6,7,8,7,6,5,4,5,6,5,4,3,2,3,4,5,6, %U A232191 5,4,3,3,4,5,6,7,8,7,6,5,4,3,2,3,4,5,6 %N A232191 A walk based on the digits of Pi (A000796). %C A232191 Pi = 3.14159265358979323846.... %C A232191 Between 3 and 1 we place 2. %C A232191 Between 1 and 4 we place 2 and 3. %C A232191 Between 4 and 1 we place 3 and 2. %C A232191 Between 1 and 5 we place 2, 3, and 4. %C A232191 Between 5 and 9 we place 6, 7, and 8. %C A232191 Between 9 and 2 we place 8, 7, 6, 5, 4 and 3. %C A232191 Between 2 and 6 we place 3, 4 and 5. %C A232191 Between 6 and 5 we place nothing. %C A232191 Between 5 and 3 we place 4, and so on. %C A232191 This gives: %C A232191 3, 2, 1, 2, 3, 4, 3, 2, 1, 2, 3, 4, 5, 6, 7, 8, 9, 8, 7, 6, 5, 4, 3, 2, 3, 4, 5, 6, 5, 4, 3, 4, 5, ... %C A232191 This could be called a walk (or promenade) on the digits of Pi. %Y A232191 Cf. A000796 %K A232191 nonn,easy,base %O A232191 1,1 %A A232191 _Philippe Deléham_, Nov 20 2013