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 A152855 #15 Jan 20 2024 18:28:55 %S A152855 1,2,0,2,0,1,2,0,2,0,1,2,0,2,0,1,2,0,2,0,1,2,0,2,0,1,2,0,2,0,1,2,0,2, %T A152855 0,1,2,0,2,0,1,2,0,2,0,1,2,0,2,0,1,2,0,2,0,1,2,0,2,0,1,2,0,2,0,1,2,0, %U A152855 2,0,1,2,0,2,0,1,2,0,2,0,1,2,0,2,0,1,2,0,2,0,1,2,0,2,0,1,2,0,2,0,1,2,0,2,0 %N A152855 Period 5: Repeat [1, 2, 0, 2, 0]. %H A152855 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,1) %F A152855 a(n+5) = a(n) with a(0) = 1, a(1) = a(3) = 2 and a(2) = a(4) = 0. %F A152855 O.g.f.: f(z) = (1+2*z+2*z^3)/(1-z^5). %F A152855 a(n) = 1+(-1/5*((5-5^(1/2))^(1/2)-(5+5^(1/2))^(1/2))*2^(1/2))*sin(2*n*Pi/5)+(1/5*((5-5^(1/2))^(1/2)+(5+5^(1/2))^(1/2))*2^(1/2))*sin(4*n*Pi/5). %t A152855 PadRight[{},120,{1,2,0,2,0}] (* _Harvey P. Dale_, Dec 17 2022 *) %Y A152855 Cf. A026039. %K A152855 easy,nonn %O A152855 0,2 %A A152855 _Richard Choulet_, Dec 14 2008