A003819 a(1)=a(2)=1, a(n+1) = (a(n)^4 +1)/a(n-1).

1, 1, 2, 17, 41761, 178910008847318626, 24533960352822051755918055684179592096697004630540952679692131057

Offset: 1

Author

Waldemar Pompe (pompe(AT)zodiac1.mimuw.edu.pl)

Keywords

• nonn

Programs

Maple

A003819 := proc(n) option remember; if n <= 2 then 1 else (A003819(n-1)^4+1)/A003819(n-2); fi; end;

Mathematica

nxt[{a_,b_}]:={b,(b^4+1)/a}; Transpose[NestList[nxt,{1,1},6]][[1]] (* Harvey P. Dale, Jun 21 2015 *)