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 A143807 #4 Jun 28 2025 15:43:02 %S A143807 1,2,2,22,40,18,2468,11698,11426,2178,74056628 %N A143807 Number of geodesics between a pair of perfect states in the Tower of Hanoi with 4 pegs and n disks. %Y A143807 Sequence A007664 gives the lengths of the geodesics being counted by the present sequence (conjecturally this is true for all n; experimentally it is true for the first 20 terms) %K A143807 nonn,hard,more %O A143807 1,2 %A A143807 Jason Behrstock (jason(AT)math.columbia.edu), Sep 01 2008