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 A317630 #11 Aug 02 2018 08:00:39 %S A317630 0,2,1,4,3,6,5,8,7,80,9,13,12,15,14,17,16,19,18,24,23,26,25,28,27,34, %T A317630 29,36,35,38,37,45,39,47,46,49,48,57,56,59,58,68,67,120,10,21,20,31, %U A317630 30,40,32,42,41,50,43,52,51,54,53,61,60,63,62,65,64,71,70,73,72,75,74,81,76,83,82,85,84,87,86,91,90,93,92,95 %N A317630 Lexicographically first sequence of different terms, starting with a(1) = 0 and showing a 1-step roller coaster of terms together with a 1-step roller coaster of digits (see the Comments section). %C A317630 Every term a(n) > 0 of the sequence stands between two terms bigger than a(n) or between two terms smaller than a(n); this is also true for every digit d > 0 of the sequence that stands between two digits bigger than d or between two digits smaller than d. %H A317630 Lars Blomberg, <a href="/A317630/b317630.txt">Table of n, a(n) for n = 1..10000</a> %e A317630 The sequence starts with 0,2,1,4,3,6,5,8,7,80,9,13,12,15,14,17,16,19... %e A317630 If we consider the terms, we see indeed that 0 < 2 > 1 < 4 > 3 < 6 > 5 < 8 > 7 < 80 > 9 < 13 > 12 < 15 > 14 < 17 > 16 < 19... and if we consider the digits, we see also that 0 < 2 > 1 < 4 > 3 < 6 > 5 < 8 > 7 < 8 > 0 < 9 > 1 < 3 > 1 < 2 > 1 < 5 > 1 < 4 > 1 < 7 > 1 < 6 > 1 < 9... %e A317630 So no matter the elements considered (terms, digits), those elements seem to ride on a 1-step roller-coaster: up, down, up, down, up, etc. %Y A317630 Cf. A014681 (a 1-step roller coaster of terms only) and A317548 (a 1-step roller coaster of digits only). %K A317630 nonn,base,look %O A317630 1,2 %A A317630 _Eric Angelini_ and _Jean-Marc Falcoz_, Aug 02 2018