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 A110213 #8 Jun 13 2015 00:51:52
%S A110213 1,-7,35,-169,803,-3805,18011,-85237,403355,-1908709,9032123,
%T A110213 -42740485,202250171,-957058117,4528847675,-21430737349,101411338043,
%U A110213 -479883604165,2270833596731,-10745699955397,50849198151995,-240620989179589,1138630746165563,-5388058541915845
%N A110213 a(n+3) = 6*a(n) - 5*a(n+2), a(0) = 1, a(1) = -7, a(2) = 35.
%H A110213 Harvey P. Dale, <a href="/A110213/b110213.txt">Table of n, a(n) for n = 0..1000</a>
%H A110213 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (-5,0,6).
%F A110213 G.f. (-1+2*x)/((x-1)*(6*x^2+6*x+1))
%F A110213 a(x)=(3-Sqrt[3]+(7-8*Sqrt[3])(-3+Sqrt[3])^x+(-3-Sqrt[3])^x (-10+9*Sqrt[3]))/(13*(-3+Sqrt[3])). - _Harvey P. Dale_, Mar 01 2015
%p A110213 seriestolist(series((-1+2*x)/((x-1)*(6*x^2+6*x+1)), x=0,25)); -or- Floretion Algebra Multiplication Program, FAMP Code: 2baseksumseq[A*B] with A = + 'i + 'ii' + 'ij' + 'ik' and B = + .5'i - .5'j + .5'k + .5i' + .5j' - .5k' - .5'ij' - .5'ik' + .5'ji' + .5'ki' Sumtype is set to: sum[(Y[0], Y[1], Y[2]),mod(3)
%t A110213 LinearRecurrence[{-5,0,6},{1,-7,35},30] (* _Harvey P. Dale_, Mar 01 2015 *)
%Y A110213 Cf. A110210, A110211, A110212.
%K A110213 easy,sign
%O A110213 0,2
%A A110213 _Creighton Dement_, Jul 16 2005