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 A185357 #22 Feb 16 2025 08:33:13
%S A185357 1,1,2,3,5,8,13,21,34,55,89,144,233,377,610,987,1597,2584,4180,6763,
%T A185357 10942,17703,28642,46340,74974,121301,196254,317521,513720,831152,
%U A185357 1344728,2175647,3519998,5695035,9214046,14907484,24118947,39022252,63134437,102145749
%N A185357 Expansion of 1/(1 - x - x^2 + x^18 - x^20).
%C A185357 Limiting ratio is 1.61791..., the real root of -1 + x^2 - x^18 - x^19 + x^20. Signature in Mathematica is:
%C A185357 -CoefficientList[1 - x - x^2 + x^18 - x^20, x]
%C A185357 {-1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 1}.
%C A185357 The sequence agrees with the Fibonacci numbers (A000045) for the first 18 terms.
%H A185357 G. C. Greubel, <a href="/A185357/b185357.txt">Table of n, a(n) for n = 0..1000</a>
%H A185357 David Terr and Eric W. Weisstein, <a href="https://mathworld.wolfram.com/PisotNumber.html">MathWorld: Pisot Number</a>
%H A185357 <a href="/index/Rec#order_20">Index entries for linear recurrences with constant coefficients</a>, signature (1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 1).
%t A185357 CoefficientList[Series[1/(1 - x - x^2 + x^18 - x^20), {x, 0, 50}], x]
%o A185357 (PARI) Vec(1/(1-x-x^2+x^18-x^20) + O(x^50)) \\ _G. C. Greubel_, Nov 16 2016
%Y A185357 Cf. A117791, A107293, A204631.
%K A185357 nonn,easy
%O A185357 0,3
%A A185357 _Roger L. Bagula_, Jan 21 2012