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 A152890 #15 Jun 02 2025 01:15:23 %S A152890 4,1,4,0,1,4,1,4,0,1,4,1,4,0,1,4,1,4,0,1,4,1,4,0,1,4,1,4,0,1,4,1,4,0, %T A152890 1,4,1,4,0,1,4,1,4,0,1,4,1,4,0,1,4,1,4,0,1 %N A152890 Periodic sequence [4,1,4,0,1] of period 5. %H A152890 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,1). %F A152890 a(n+5) = a(n). %F A152890 G.f: (4+z+4*z^2+z^4)/(1-z^5). %F A152890 a(n) = 2+(-1/5*5^(1/2)+1)*cos(2*n*Pi/5)+(2/5*2^(1/2)*(5-5^(1/2))^(1/2))*sin(2*n*Pi/5)+(1/5*5^(1/2)+1)*cos(4*n*Pi/5)+(-2/5*2^(1/2)*(5+5^(1/2))^(1/2))*sin(4*n*Pi/5) %Y A152890 Cf. A026051. %K A152890 easy,nonn,less %O A152890 0,1 %A A152890 _Richard Choulet_, Dec 14 2008