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 A240526 #36 Feb 28 2025 05:58:21
%S A240526 7,23,76,284,1072,4208,16576,65984,262912,1050368,4197376,16784384,
%T A240526 67121152,268464128,1073790976,4295081984,17180065792,68719935488,
%U A240526 274878693376,1099513462784,4398049656832,17592193384448,70368756760576,281475006070784,1125899957174272
%N A240526 a(n) = 2^(n-2)*(2^(n+4)-(-1)^n+13).
%H A240526 Vincenzo Librandi, <a href="/A240526/b240526.txt">Table of n, a(n) for n = 0..200</a>
%H A240526 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (4,4,-16).
%F A240526 G.f.: (7-5*x-44*x^2)/(1-4*x-4*x^2+16*x^3).
%F A240526 a(n) = 4*a(n-1)+4*a(n-2)-16*a(n-3) for n>2.
%p A240526 A240526:=n->2^(n-2)*(2^(n+4)-(-1)^n+13); seq(A240526(n), n=0..30); # _Wesley Ivan Hurt_, Apr 10 2014
%t A240526 CoefficientList[Series[(7 - 5 x - 44 x^2)/(1 - 4 x - 4 x^2 + 16 x^3), {x, 0, 30}], x]
%o A240526 (Magma) [2^(n-2)*(2^(n+4)-(-1)^n+13): n in [0..25]];
%o A240526 (Magma) I:=[7,23,76]; [n le 3 select I[n] else 4*Self(n-1)+4*Self(n-2)-16*Self(n-3): n in [1..30]];
%o A240526 (PARI) a(n)=(2^(n+4)-(-1)^n+13)<<(n-2) \\ _Charles R Greathouse IV_, Aug 26 2014
%Y A240526 Cf. A225826.
%K A240526 nonn,easy
%O A240526 0,1
%A A240526 _Vincenzo Librandi_, Apr 07 2014