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 A182467 #22 Aug 01 2015 09:13:54 %S A182467 36,90,198,414,846,1710,3438,6894,13806,27630,55278,110574,221166, %T A182467 442350,884718,1769454,3538926,7077870,14155758,28311534,56623086, %U A182467 113246190,226492398,452984814,905969646,1811939310,3623878638,7247757294,14495514606,28991029230 %N A182467 a(n) = 3a(n-1) - 2a(n-2) with a(0)=36 and a(1)=90. %C A182467 Number of vertices into building blocks of 3d objects with 9 vertices. %H A182467 Vincenzo Librandi, <a href="/A182467/b182467.txt">Table of n, a(n) for n = 0..1000</a> %H A182467 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (3, -2). %F A182467 a(n) = a(n-1)*2 + 18 %F A182467 G.f.: -((18*(x-2))/(2*x^2-3*x+1)). - _Harvey P. Dale_, Apr 29 2013 %F A182467 a(n) = 18*A153893(n). - _Michel Marcus_, Jun 01 2014 %e A182467 a(0) = 9+18+9; %e A182467 a(1) = 9+18+36+18+9; %e A182467 a(2) = 9+18+36+72+36+18+9; %e A182467 a(3) = 9+18+36+72+144+72+36+18+9. %t A182467 LinearRecurrence[{3,-2},{36,90},30] (* or *) CoefficientList[Series[(-18(x-2))/(1-3x+2x^2),{x,0,30}],x] (* _Harvey P. Dale_, Apr 29 2013 *) %Y A182467 Cf. A000045, A028399, A038578, A089143, A173033, A182461, A182462, A182464, A182465, A182466. %K A182467 nonn,easy %O A182467 0,1 %A A182467 _Odimar Fabeny_, Apr 30 2012