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 A166867 #14 May 10 2024 16:51:42
%S A166867 0,1,8,27,84,237,644,1695,4376,11129,28000,69859,173180,427141,
%T A166867 1049308,2569447,6275584,15295377,37215864,90426155,219466276,
%U A166867 532154909,1289368500,3122076719,7555891560,18278599081,44202568208,106862692467
%N A166867 a(n) = Pell(n+3) - Jacobsthal(n+4).
%H A166867 G. C. Greubel, <a href="/A166867/b166867.txt">Table of n, a(n) for n = 0..1000</a>
%H A166867 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (3,1,-5,-2).
%F A166867 G.f.: x(1+5x+2x^2)/((1-x-2x^2)(1-2x-x^2)).
%F A166867 a(n) = A166868(n) + A097076(n+1) - A000129(n+2).
%F A166867 a(n) = 3*a(n-1) + a(n-2) - 5*a(n-3) - 2*a(n-4). - _G. C. Greubel_, May 25 2016
%t A166867 LinearRecurrence[{3, 1, -5, -2}, {0, 1, 8, 27}, 50] (* _G. C. Greubel_, May 25 2016 *)
%Y A166867 Cf. A000129, A097076, A166868.
%K A166867 easy,nonn
%O A166867 0,3
%A A166867 _Paul Barry_, Oct 22 2009