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 A294152 #38 Feb 16 2025 08:33:51
%S A294152 0,2,11,38,112,309,828,2190,5759,15106,39580,103657,271416,710618,
%T A294152 1860467,4870814,12752008,33385245,87403764,228826086,599074535,
%U A294152 1568397562,4106118196,10749957073,28143753072,73681302194,192900153563,505019158550,1322157322144
%N A294152 Chromatic invariant of the n-antiprism graph.
%C A294152 Extended to a(1)-a(2) using the formula/recurrence.
%H A294152 Colin Barker, <a href="/A294152/b294152.txt">Table of n, a(n) for n = 1..1000</a>
%H A294152 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/AntiprismGraph.html">Antiprism Graph</a>
%H A294152 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ChromaticInvariant.html">Chromatic Invariant</a>
%H A294152 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (5, -8, 5, -1).
%F A294152 a(n) = A005248(n) - 2*n - 1.
%F A294152 a(n) = phi^(2*n) + phi^(-2*n) - 2*n - 1.
%F A294152 a(n) = 5*a(n-1) - 8*a(n-2) + 5*a(n-3) - a(n-4).
%F A294152 G.f.: x^2*(2 + x - x^2)/((-1 + x)^2*(1 - 3*x + x^2)).
%F A294152 a(n) = -1 + ((3-sqrt(5))/2)^n + ((3+sqrt(5))/2)^n - 2*n. - _Colin Barker_, Nov 16 2017
%t A294152 Table[LucasL[2 n] - 2 n - 1, {n, 3, 20}]
%t A294152 LinearRecurrence[{5, -8, 5, -1}, {0, 2, 11, 38}, 20]
%t A294152 CoefficientList[Series[(x (2 + x - x^2))/((-1 + x)^2 (1 - 3 x + x^2)), {x, 0, 20}], x]
%o A294152 (PARI) concat(0, Vec(x^2*(2 + x - x^2)/((-1 + x)^2*(1 - 3*x + x^2)) + O(x^40))) \\ _Colin Barker_, Nov 16 2017
%Y A294152 Cf. A005248 (lucasl(2*n)).
%K A294152 nonn,easy
%O A294152 1,2
%A A294152 _Eric W. Weisstein_, Nov 16 2017