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 A107383 #34 Jul 31 2025 16:55:58 %S A107383 0,1,1,2,4,6,12,20,36,64,112,200,352,624,1104,1952,3456,6112,10816, %T A107383 19136,33856,59904,105984,187520,331776,587008,1038592,1837568, %U A107383 3251200,5752320,10177536,18007040,31859712,56369152,99733504,176457728 %N A107383 a(n) = 2*a(n-2) + 2*a(n-3). %C A107383 Also the number of maximal independent vertex sets (and minimal vertex covers) in the 2 X (n-2) king graph. - _Eric W. Weisstein_, Aug 07 2017 %H A107383 Michael De Vlieger, <a href="/A107383/b107383.txt">Table of n, a(n) for n = 0..4037</a> %H A107383 Igor Pak, Boris Shapiro, Ilya Smirnov, and Ken-ichi Yoshida, <a href="https://staff.math.su.se/shapiro/Articles/Hilbert-Kunz.pdf">Hilbert-Kunz multiplicity of quadrics via the Ehrhart theory</a>, Stockholm Univ. (Sweden, 2025). See p. 4. %H A107383 Noriaki Sannomiya, Hosho Katsura, and Yu Nakayama, <a href="https://arxiv.org/abs/1612.02285">Supersymmetry breaking and Nambu-Goldstone fermions with cubic dispersion</a>, arXiv:1612.02285 [cond-mat.str-el], 2016. See Table II, line 1. %H A107383 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/KingGraph.html">King Graph</a> %H A107383 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MaximalIndependentVertexSet.html">Maximal Independent Vertex Set</a> %H A107383 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MinimalVertexCover.html">Minimal Vertex Cover</a> %H A107383 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (0,2,2). %F A107383 G.f.: x*(1+x)/(1-2*x^2-2*x^3). %F A107383 a(n) = (-1)^(n+1)*A078025(n-1). %F A107383 Limit_{n->oo} a(n)/a(n-1) = 1.7692923... . %F A107383 a(n)+a(n+1) = A061279(n). - _R. J. Mathar_, Dec 01 2011 %t A107383 m = 2; a[0] = 0; a[1] = 1; a[2] = 1; a[3] = 2; a[n_] := a[n] = a[n - 1] + m*a[n - 2] - m*a[n - 4]; Table[a[n], {n, 0, 50}] (* edited and corrected by _Harvey P. Dale_, May 07 2014 *) %t A107383 LinearRecurrence[{0, 2, 2}, {0, 1, 1}, 40] (* _Harvey P. Dale_, May 07 2014 *) %t A107383 Table[RootSum[-2 - 2 # + #^3 &, 5 #^n + 8 #^(n + 1) + #^(n + 2) &]/19, {n, 20}] (* _Eric W. Weisstein_, Aug 07 2017 *) %t A107383 CoefficientList[Series[-((2 (1 + 2 x + x^2))/(-1 + 2 x^2 + 2 x^3)), {x, 0, 20}], x] (* _Eric W. Weisstein_, Aug 07 2017 *) %Y A107383 Cf. A061279, A078025. %K A107383 nonn,easy %O A107383 0,4 %A A107383 _Roger L. Bagula_, May 24 2005 %E A107383 Definition replaced by recurrence by the Associate Editors of the OEIS, Sep 28 2009