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 A206268 #27 Dec 09 2020 19:58:49
%S A206268 1,1,1,3,4,8,13,23,39,67,114,194,329,557,941,1587,2672,4492,7541,
%T A206268 12643,21171,35411,59166,98758,164689,274393,456793,759843,1263004,
%U A206268 2097872,3482269,5776559,9576639,15867427,26276106,43489802,71944217,118958597,196605701
%N A206268 Number of compositions of n with at most one 1.
%H A206268 Jair Taylor, <a href="/A206268/b206268.txt">Table of n, a(n) for n = 0..499</a>
%H A206268 Ricardo Gómez Aíza, <a href="https://arxiv.org/abs/2009.02669">Symbolic dynamical scales: modes, orbitals, and transversals</a>, arXiv:2009.02669 [math.DS], 2020.
%F A206268 G.f.: (2*x^3 - 2*x^2 - x + 1)/(x^4 + 2*x^3 - x^2 - 2*x + 1).
%e A206268 We have a(3) = 3 since 3 = 1 + 2 = 2+1. A(2) = 1 since 2 is the only composition of 2 that does not have more than one 1.
%t A206268 CoefficientList[Series[(2 x^3 - 2 x^2 - x + 1)/(x^4 + 2 x^3 - x^2 - 2 x + 1), {x, 0, 38}], x] (* _Michael De Vlieger_, Dec 09 2020 *)
%o A206268 (Sage) R.<x> = PowerSeriesRing(QQ)
%o A206268 f = (2*x^3 - 2*x^2 - x + 1)/(x^4 + 2*x^3 - x^2 - 2*x + 1)
%o A206268 print(f.list())
%K A206268 nonn
%O A206268 0,4
%A A206268 _Jair Taylor_, Feb 18 2012