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 A335688 #20 Jul 18 2020 18:25:13
%S A335688 1,1,2,1,3,2,6,5,126,115,297108,1370225,200590993732752,
%T A335688 531984953824739375,27113273919595441588692453206842987776,
%U A335688 56653874513318656544104537473266204894369805859375
%N A335688 Numerator of b(n), where b(1)=b(2)=1, and for n>2, b(n) = (1+b(n-2))/b(n-1).
%C A335688 With a tiny change in subscripts {b(n)} becomes the Lyness 5-cycle, a sequence of period 5, as illustrated in A076839.
%e A335688 1, 1, 2, 1, 3, 2/3, 6, 5/18, 126/5, 115/2268, 297108/575, 1370225/673840944, 200590993732752/787879375, ...
%Y A335688 Cf. A076839, A335689.
%K A335688 nonn,frac
%O A335688 1,3
%A A335688 _N. J. A. Sloane_, Jul 17 2020