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 A307676 #20 Jul 31 2021 08:59:02
%S A307676 1,0,2,4,6,14,22,46,74,138,236,406,698,1182,1994,3342,5590,9274,15386,
%T A307676 25380,41818,68670,112586,184210,300940,490962,800026,1302278,2118008,
%U A307676 3442042,5590092,9073632,14720738,23872776,38700910,62720726,101622398,164617032
%N A307676 Expansion of Product_{k>=1} (1 - x^k*(1 - x))/(1 - x^k*(1 + x)).
%H A307676 Seiichi Manyama, <a href="/A307676/b307676.txt">Table of n, a(n) for n = 0..1000</a>
%F A307676 G.f.: exp(Sum_{k>=1} x^k * Sum_{d|k} ((1+x)^d - (1-x)^d)/d).
%F A307676 a(n) ~ phi^(n+4) / sqrt(5), where phi = A001622 is the golden ratio. - _Vaclav Kotesovec_, Jul 31 2021
%t A307676 nmax = 50; CoefficientList[Series[Product[(1 - x^k*(1 - x))/(1 - x^k*(1 + x)), {k, 1, nmax}], {x, 0, nmax}], x] (* _Vaclav Kotesovec_, Jul 31 2021 *)
%o A307676 (PARI) N=66; x='x+O('x^N); Vec(prod(k=1, N, (1-x^k*(1-x))/(1-x^k*(1+x))))
%o A307676 (PARI) N=66; x='x+O('x^N); Vec(exp(sum(k=1, N, x^k*sumdiv(k, d, ((1+x)^d-(1-x)^d)/d))))
%Y A307676 Cf. A227681, A198197.
%K A307676 nonn
%O A307676 0,3
%A A307676 _Seiichi Manyama_, Apr 21 2019