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 A110550 #21 Dec 14 2023 05:18:19
%S A110550 1,3,2,4,4,2,3,1,1,3,2,4,4,2,3,1,1,3,2,4,4,2,3,1,1,3,2,4,4,2,3,1,1,3,
%T A110550 2,4,4,2,3,1,1,3,2,4,4,2,3,1,1,3,2,4,4,2,3,1,1,3,2,4,4,2,3,1,1,3,2,4,
%U A110550 4,2,3,1,1,3,2,4,4,2,3,1,1,3,2,4,4,2,3,1,1,3,2,4,4,2,3,1
%N A110550 Periodic {1,3,2,4,4,2,3,1}.
%C A110550 Permutation of {1,2,3,4} followed by its reversal, repeated.
%C A110550 Simple continued fraction expansion of (671 + sqrt 7241477)/2606. - _R. J. Mathar_, Mar 08 2012
%H A110550 Antti Karttunen, <a href="/A110550/b110550.txt">Table of n, a(n) for n = 0..8191</a>
%H A110550 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,0,-1,1).
%F A110550 G.f.: -(x^2+3*x+1)*(x^2-x+1) / ( (x-1)*(1+x^4) ).
%F A110550 a(n) = a(n-1) - a(n-2) + a(n-3) - a(n-4) + a(n-5) - a(n-6) + a(n-7).
%t A110550 PadRight[{}, 100, {1,3,2,4,4,2,3,1}] (* _G. C. Greubel_, Aug 31 2017 *)
%o A110550 (Scheme) (define (A110550 n) (list-ref '(1 3 2 4 4 2 3 1) (modulo n 8))) ;; _Antti Karttunen_, Aug 10 2017
%o A110550 (PARI) x='x+O('x^50); Vec((x^2+3*x+1)*(x^2-x+1)/((1-x)*(1+x^4))) \\ _G. C. Greubel_, Aug 31 2017
%Y A110550 Cf. A105198, A110549.
%K A110550 easy,nonn
%O A110550 0,2
%A A110550 _Paul Barry_, Jul 26 2005