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 A110568 #31 Dec 14 2023 05:18:12 %S A110568 1,0,2,2,0,1,1,0,2,2,0,1,1,0,2,2,0,1,1,0,2,2,0,1,1,0,2,2,0,1,1,0,2,2, %T A110568 0,1,1,0,2,2,0,1,1,0,2,2,0,1,1,0,2,2,0,1,1,0,2,2,0,1,1,0,2,2,0,1,1,0, %U A110568 2,2,0,1,1,0,2,2,0,1,1,0,2,2,0,1,1,0,2,2,0,1,1,0,2 %N A110568 Period 6: repeat [1, 0, 2, 2, 0, 1]. %C A110568 Permutation of {0, 1, 2}, followed by its reversal, repeated. %H A110568 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (1,-1,1,-1,1). %F A110568 a(n) = A078008(n) mod 3. %F A110568 G.f.: (1-x+3*x^2-x^3+x^4) / (1-x+x^2-x^3+x^4-x^5). %F A110568 a(n) = a(n-1) - a(n-2) + a(n-3) - a(n-4) + a(n-5) for n>4. %F A110568 a(n) = 1 + cos(2*Pi*n/3)/2 - sqrt(3)*sin(2*Pi*n/3)/2 - cos(Pi*n/3)/2 + sqrt(3)*sin(Pi*n/3)/6. %F A110568 a(n) = a(n-6) for n > 5. - _Wesley Ivan Hurt_, Jun 28 2016 %F A110568 a(n) = ((n-1)*(-1)^(n-1) mod 3). - _Wesley Ivan Hurt_, Jan 07 2021 %p A110568 A110568:=n->[1, 0, 2, 2, 0, 1][(n mod 6)+1]: seq(A110568(n), n=0..100); # _Wesley Ivan Hurt_, Jun 28 2016 %t A110568 Mod[#,3]&/@CoefficientList[Series[(1-x)/(1-x-2x^2),{x,0,100}],x] (* _Harvey P. Dale_, Mar 30 2011 *) %t A110568 PadRight[{}, 100, {1, 0, 2, 2, 0, 1}] (* _Wesley Ivan Hurt_, Jun 28 2016 *) %t A110568 LinearRecurrence[{1,-1,1,-1,1},{1,0,2,2,0},100] (* _Harvey P. Dale_, Apr 03 2019 *) %o A110568 (Magma) &cat [[1, 0, 2, 2, 0, 1]^^30]; // _Wesley Ivan Hurt_, Jun 28 2016 %o A110568 (PARI) x='x+O('x^50); Vec((1-x+3*x^2-x^3+x^4)/(1-x+x^2-x^3+x^4-x^5)) \\ _G. C. Greubel_, Aug 31 2017 %Y A110568 Cf. A078008, A088689, A105198, A110549, A110550, A110551, A110569. %K A110568 easy,nonn %O A110568 0,3 %A A110568 _Paul Barry_, Jul 27 2005 %E A110568 Name changed by _Wesley Ivan Hurt_, Jun 28 2016