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 A178675 #28 Sep 12 2023 18:01:14
%S A178675 5,8,20,68,260,1028,4100,16388,65540,262148,1048580,4194308,16777220,
%T A178675 67108868,268435460,1073741828,4294967300,17179869188,68719476740,
%U A178675 274877906948,1099511627780,4398046511108,17592186044420,70368744177668,281474976710660,1125899906842628
%N A178675 a(n) = 4^n + 4.
%H A178675 Vincenzo Librandi, <a href="/A178675/b178675.txt">Table of n, a(n) for n = 0..1000</a>
%H A178675 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (5,-4).
%F A178675 a(n) = 4*(a(n-1) - 3) with n > 0, a(0)=5.
%F A178675 G.f.: ( 5-17*x ) / ( (1-4*x)*(1-x) ). - _R. J. Mathar_, Jan 05 2011
%F A178675 a(n) = 5*a(n-1) - 4*a(n-2). - _Vincenzo Librandi_, Jun 18 2013
%F A178675 E.g.f.: exp(4*x) + 4*exp(x). - _G. C. Greubel_, Jan 27 2019
%t A178675 Table[4^n +4, {n, 0, 40}] (* or *) CoefficientList[Series[(5-17x)/((4x - 1)(x-1)), {x, 0, 30}], x] (* _Vincenzo Librandi_, Jun 18 2013 *)
%t A178675 LinearRecurrence[{5,-4},{5,8},30] (* _Harvey P. Dale_, Sep 12 2023 *)
%o A178675 (Magma)[4^n+4: n in [0..35]];
%o A178675 (Magma) I:=[5, 8]; [n le 2 select I[n] else 5*Self(n-1)-4*Self(n-2): n in [1..30]]; // _Vincenzo Librandi_, Jun 18 2013
%o A178675 (PARI) vector(40, n, n--; 4^n+4) \\ _G. C. Greubel_, Jan 27 2019
%o A178675 (Sage) [4^n+4 for n in range(40)] # _G. C. Greubel_, Jan 27 2019
%o A178675 (GAP) List([0..30], n -> 4^n + 4); # _G. C. Greubel_, Jan 27 2019
%Y A178675 Cf. A052548, A178674, A178676, A178681.
%K A178675 nonn,easy
%O A178675 0,1
%A A178675 _Vincenzo Librandi_, Dec 25 2010