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 A225928 #18 Oct 09 2017 10:15:01
%S A225928 29,113,1169,16913,264209,4202513,67141649,1073872913,17180393489,
%T A225928 274880004113,4398054899729,70368777732113,1125900041060369,
%U A225928 18014399046352913,288230378299195409,4611686027017322513,73786976329197944849,1180591620854850256913
%N A225928 a(n) = 4*16^n + 8*4^n + 17.
%C A225928 Number of conjugacy classes in Ree group 2F4(2*4^n).
%H A225928 Eric M. Schmidt, <a href="/A225928/b225928.txt">Table of n, a(n) for n = 0..500</a>
%H A225928 Frank Luebeck, <a href="http://www.math.rwth-aachen.de/~Frank.Luebeck/chev/nrclasses/nrclasses.html">Numbers of Conjugacy Classes in Finite Groups of Lie Type</a>.
%H A225928 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (21,-84,64).
%F A225928 G.f.: 17/(1-x) + 8/(1-4x) + 4/(1-16x).
%F A225928 a(n) = 21*a(n-1) - 84*a(n-2) + 64*a(n-3) for n > 2. - _Wesley Ivan Hurt_, Oct 08 2017
%t A225928 LinearRecurrence[{21,-84,64},{29,113,1169},20] (* _Harvey P. Dale_, May 06 2016 *)
%o A225928 (Sage) [4*16^n + 8*4^n + 17 for n in [0..20]]
%o A225928 (PARI) a(n)=4*16^n+8*4^n+17 \\ _Charles R Greathouse IV_, May 22 2013
%Y A225928 Cf. A188161, A224790, A225929 - A225938.
%K A225928 nonn,easy
%O A225928 0,1
%A A225928 _Eric M. Schmidt_, May 21 2013