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 A113437 #16 Jul 08 2024 21:33:08
%S A113437 1,3,11,41,154,581,2197,8317,31501,119338,452141,1713111,6490879,
%T A113437 24593701,93184802,353074657,1337790401,5068852073,19205744921,
%U A113437 72770053106,275723780329,1044710007771,3958378188707,14998188734897
%N A113437 Second row of A113435.
%H A113437 G. C. Greubel, <a href="/A113437/b113437.txt">Table of n, a(n) for n = 0..1000</a>
%H A113437 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (7,-15,11,-1).
%F A113437 a(n) = A113435(3*n+1).
%F A113437 a(n) = 7*a(n-1) - 15*a(n-2) + 11*a(n-3) - a(n-4).
%F A113437 G.f.: (1-4*x+5*x^2-2*x^3)/(1-7*x+15*x^2-11*x^3+x^4).
%t A113437 CoefficientList[Series[(1 - 4*x + 5*x^2 - 2*x^3)/(1 - 7*x + 15*x^2 - 11*x^3 + x^4), {x,0,50}], x] (* _G. C. Greubel_, Mar 11 2017 *)
%t A113437 LinearRecurrence[{7,-15,11,-1},{1,3,11,41},30] (* _Harvey P. Dale_, May 09 2018 *)
%o A113437 (PARI) x='x+O('x^50); Vec((1-4*x+5*x^2-2*x^3)/(1-7*x+15*x^2-11*x^3+x^4)) \\ _G. C. Greubel_, Mar 11 2017
%Y A113437 Cf. A113435.
%K A113437 nonn,easy
%O A113437 0,2
%A A113437 _Floor van Lamoen_, Nov 04 2005