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 A171471 #7 Mar 22 2018 16:37:13
%S A171471 35,225,837,3213,12573,49725,197757,788733,3150333,12592125,50350077,
%T A171471 201363453,805380093,3221372925,12885196797,51540197373,206159609853,
%U A171471 824636080125,3298539601917,13194148970493,52776577007613
%N A171471 a(n) = 6*a(n-1)-8*a(n-2)-9 for n > 2; a(0) = 35, a(1) = 225, a(2) = 837.
%C A171471 Related to Reverse and Add trajectory of 22 in base 2: A061561(4*n+1) = a(n).
%H A171471 Vincenzo Librandi, <a href="/A171471/b171471.txt">Table of n, a(n) for n = 0..500</a>
%H A171471 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (7,-14,8).
%F A171471 a(n) = 48*4^n+18*2^n-3 for n > 0.
%F A171471 G.f.: (35-20*x-248*x^2+224*x^3)/((1-x)*(1-2*x)*(1-4*x)).
%t A171471 LinearRecurrence[{7,-14,8},{35,225,837,3213},30] (* _Harvey P. Dale_, Mar 22 2018 *)
%o A171471 (PARI) {m=22; v=concat([35, 225, 837], vector(m-3)); for(n=4, m, v[n]=6*v[n-1]-8*v[n-2]-9); v}
%Y A171471 Cf. A061561, A171470, A171472, A171473.
%K A171471 nonn,easy
%O A171471 0,1
%A A171471 _Klaus Brockhaus_, Dec 09 2009