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 A306575 #30 Jul 01 2019 09:20:41
%S A306575 1,1,2,3,6,11,21,40,77,148,285,550,1061,2049,3957,7644,14768,28535,
%T A306575 55138,106549,205902,397906,768967,1486070,2871932,5550233,10726300,
%U A306575 20729542,40061784,77423250,149628008,289170949,558851751,1080037175,2087280839,4033881485
%N A306575 Expansion of 1/(1 - x - x^2/(1 - x^2 - x^3/(1 - x^3 - x^4/(1 - x^4 - x^5/(1 - ...))))), a continued fraction.
%F A306575 a(n) ~ c * d^n, where d = 1.9326019136649450138850556203... and c = 0.389707331111778150048054243... - _Vaclav Kotesovec_, Jul 01 2019
%t A306575 nmax = 35; CoefficientList[Series[1/(1 - x + ContinuedFractionK[-x^k, 1 - x^k, {k, 2, nmax}]), {x, 0, nmax}], x]
%Y A306575 Cf. A029838, A083365, A088352.
%K A306575 nonn
%O A306575 0,3
%A A306575 _Ilya Gutkovskiy_, Jun 25 2019