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 A305029 #29 Dec 12 2023 07:47:09
%S A305029 1,2,2,2,2,0,-2,-2,-2,-2,0,2,2,2,2,0,-2,-2,-2,-2,0,2,2,2,2,0,-2,-2,-2,
%T A305029 -2,0,2,2,2,2,0,-2,-2,-2,-2,0,2,2,2,2,0,-2,-2,-2,-2,0,2,2,2,2,0,-2,-2,
%U A305029 -2,-2,0,2,2,2,2,0,-2,-2,-2,-2,0,2,2,2,2,0,-2,-2,-2,-2
%N A305029 Period 10 sequence [ 0, 2, 2, 2, 2, 0, -2, -2, -2, -2, ...] except a(0) = 1.
%C A305029 If m is odd, (Sum_{k=0..m} x^k)/(Sum_{k=0..m} (-x)^k) = (1+x)/(1-x).
%H A305029 Seiichi Manyama, <a href="/A305029/b305029.txt">Table of n, a(n) for n = 0..10000</a>
%F A305029 G.f.: (1 + x + x^2 + x^3 + x^4)/(1 - x + x^2 - x^3 + x^4).
%o A305029 (PARI) N=66; x='x+O('x^N); Vec(((sum(k=0, 4, x^k))/(sum(k=0, 4, (-x)^k))))
%Y A305029 Cf. A040000 (m is odd), A000007 (m=0), A184334 (m=2), this sequence (m=4).
%K A305029 easy,sign
%O A305029 0,2
%A A305029 _Seiichi Manyama_, May 24 2018