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 A320986 #5 Oct 25 2018 20:35:52 %S A320986 0,1,4,17,276,17681,18105620,1186569930001,79629360058944734484, %T A320986 350213629188686097286494407640337, %U A320986 103364819020299355365011185381334444307580296786887956 %N A320986 Fibonacci rabbit sequence number n coded in base four. %H A320986 Alois P. Heinz, <a href="/A320986/b320986.txt">Table of n, a(n) for n = 0..16</a> %p A320986 b:= proc(n) option remember; `if`(n<2, [n$2], [b(n-1)[1]* %p A320986 4^b(n-1)[2]+b(n-2)[1], b(n-1)[2]+b(n-2)[2]]) %p A320986 end: %p A320986 a:= n-> b(n)[1]: %p A320986 seq(a(n), n=0..11); %Y A320986 Column k=4 of A144287. %K A320986 nonn %O A320986 0,3 %A A320986 _Alois P. Heinz_, Oct 25 2018