%I #8 Aug 26 2016 09:41:50
%S 1,5,20,75,288,1094,4171,15897,60565,230816,879521,3351544,12771524,
%T 48667365,185453453,706693601,2692945820,10261812539,39103937948,
%U 149010523846,567823518619,2163763618201,8245296020629,31419747421972,119728937140293,456242317652464,1738569283271528
%N Expansion of (1+4*x+8*x^2+8*x^3+7*x^4+4*x^5+2*x^6) / (1-x-7*x^2-12*x^3-6*x^4-7*x^5-4*x^6-2*x^7).
%H Colin Barker, <a href="/A275909/b275909.txt">Table of n, a(n) for n = 0..1000</a>
%H T. Doslic, T. Short, <a href="http://arxiv.org/abs/1511.00590">Maximal matchings in polyspiro and benzenoid chains</a>, arXiv:1511.00590, [math.CO], 2015. See Th. 4.4.
%H <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (1,7,12,6,7,4,2).
%F a(n) = 2*a(n-1)+6*a(n-2)+5*a(n-3)-6*a(n-4)+a(n-5)-3*a(n-6)-2*a(n-7)-2*a(n-8) for n>6. - _Colin Barker_, Aug 26 2016
%o (PARI) Vec((1+4*x+8*x^2+8*x^3+7*x^4+4*x^5+2*x^6)/(1-x-7*x^2-12*x^3-6*x^4-7*x^5-4*x^6-2*x^7) + O(x^30)) \\ _Colin Barker_, Aug 26 2016
%K nonn,easy
%O 0,2
%A _N. J. A. Sloane_, Aug 26 2016