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 A196836 #15 Oct 24 2024 02:20:32
%S A196836 2,5,15,50,177,650,2445,9350,36177,141170,554325,2186750,8656377,
%T A196836 34355690,136617405,544061750,2169039777,8654570210,34553579685,
%U A196836 138020346350,551499730377,2204254480730,8811785649165,35231447872550,140878711512177,563373614503250
%N A196836 a(n) = (1^n + 2^n +3^n + 4^n)/2.
%C A196836 2*a(n) = A001551(n), n>=0.
%F A196836 a(n) = (1^n + 2^n + 3^n + 4^n)/2, n>=0.
%F A196836 E.g.f.: (1-exp(4*x))/(2*(exp(-x)-1)) = Sum_{j=1..4} exp(j*x)/2.
%F A196836 O.g.f.: (2-5*x)*(1-5*x+5*x^2)/(Product_{j=1..4} (1-j*x)) (via Laplace transformation of the o.g.f.).
%t A196836 Table[Total[Range[4]^n]/2, {n, 0, 40}] (* _T. D. Noe_, Oct 10 2011 *)
%Y A196836 Cf. A001551/2.
%K A196836 nonn,easy
%O A196836 0,1
%A A196836 _Wolfdieter Lang_, Oct 10 2011