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 A101608 #11 Jan 20 2021 03:29:02 %S A101608 1,2,1,3,2,3,1,2,3,1,3,2,1,2,1,3,2,3,2,1,3,1,2,3,1,2,1,3,2,3,1,2,3,1, %T A101608 3,2,1,2,3,1,2,3,2,1,3,1,3,2,1,2,1,3,2,3,1,2,3,1,3,2,1,2,1,3,2,3,2,1, %U A101608 3,1,2,3,1,2,1,3,2,3,2,1,3,1,3,2,1,2,3,1,2,3,2,1,3,1,2,3,1,2,1,3,2,3 %N A101608 Solution to Tower of Hanoi puzzle encoded in pairs with the moves (1,2),(2,3),(3,1),(2,1),(3,2),(1,3). The disks are moved from peg 1 to 2. For a tower of k disks use the first 2^k-1 number pairs. %H A101608 <a href="/index/To#Hanoi">Index entries for sequences related to Towers of Hanoi</a> %F A101608 Recurrence: a(4n+1) = (n mod 3) + 1, a(4n+2) = (n+1 mod 3) + 1, a(4n+3) = f(a(2n+1)), a(4n+4) = f(a(2n+2)), where f(1)=1, f(2)=3, f(3)=2. %e A101608 The solution to the 3-disk puzzle is (1,2),(1,3),(2,3),(1,2),(3,1),(3,2),(1,2), therefore a(1) through a(7) are the same numbers in sequence. %Y A101608 Cf. A101607. %Y A101608 If the number of disks is odd see A210243. [Y. Z. Chen, Apr 10 2012] %K A101608 nonn,easy %O A101608 1,2 %A A101608 _Ralf Stephan_, Dec 09 2004