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 A003819 #9 Jun 21 2015 09:02:01
%S A003819 1,1,2,17,41761,178910008847318626,
%T A003819 24533960352822051755918055684179592096697004630540952679692131057
%N A003819 a(1)=a(2)=1, a(n+1) = (a(n)^4 +1)/a(n-1).
%p A003819 A003819 := proc(n) option remember; if n <= 2 then 1 else (A003819(n-1)^4+1)/A003819(n-2); fi; end;
%t A003819 nxt[{a_,b_}]:={b,(b^4+1)/a}; Transpose[NestList[nxt,{1,1},6]][[1]] (* _Harvey P. Dale_, Jun 21 2015 *)
%K A003819 nonn
%O A003819 1,3
%A A003819 Waldemar Pompe (pompe(AT)zodiac1.mimuw.edu.pl)