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 A256871 #21 Sep 08 2022 08:46:12
%S A256871 6,13,30,76,216,688,2400,8896,34176,133888,529920,2108416,8411136,
%T A256871 33599488,134307840,537051136,2147844096,8590655488,34361180160,
%U A256871 137441837056,549761581056,2199034789888,8796116090880,35184418226176,140737580630016,562950137970688
%N A256871 a(n) = 2^(n-1)*(2^n+11).
%C A256871 a(A102633(n)) is a subsequence of A141549.
%H A256871 Colin Barker, <a href="/A256871/b256871.txt">Table of n, a(n) for n = 0..1000</a>
%H A256871 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (6,-8).
%F A256871 G.f.: (6-23*x)/((1-4*x)*(1-2*x)). - _Vincenzo Librandi_, Apr 24 2015
%F A256871 a(n) = 6*a(n-1)-8*a(n-2). - _Colin Barker_, Apr 26 2015
%t A256871 Table[2^(n - 1) (2^n + 11), {n, 0, 30}] (* _Vincenzo Librandi_, Apr 24 2015 *)
%t A256871 LinearRecurrence[{6,-8},{6,13},40] (* _Harvey P. Dale_, Jan 29 2022 *)
%o A256871 (PARI) A256871(n)=2^(n-1)*(2^n+11)
%o A256871 (Magma) [2^(n-1)*(2^n+11): n in [0..30]]; // _Vincenzo Librandi_, Apr 24 2015
%o A256871 (PARI) Vec((6-23*x)/((1-4*x)*(1-2*x)) + O(x^100)) \\ _Colin Barker_, Apr 26 2015
%K A256871 nonn,easy
%O A256871 0,1
%A A256871 _M. F. Hasler_, Apr 24 2015