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 A279316 #15 Sep 08 2022 08:46:18
%S A279316 0,1,2,3,3,2,1,0,1,2,3,3,2,1,0,1,2,3,3,2,1,0,1,2,3,3,2,1,0,1,2,3,3,2,
%T A279316 1,0,1,2,3,3,2,1,0,1,2,3,3,2,1,0,1,2,3,3,2,1,0,1,2,3,3,2,1,0,1,2,3,3,
%U A279316 2,1,0,1,2,3,3,2,1,0,1,2,3,3,2,1,0,1
%N A279316 Period 7: repeat [0, 1, 2, 3, 3, 2, 1].
%H A279316 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,1).
%F A279316 G.f.: x*(1 + 2*x + 3*x^2 + 3*x^3 + 2*x^4 + x^5)/(1 - x^7).
%F A279316 a(n) = (1/2) * Sum_{i=1..2n} (-1)^floor((i-1)/7).
%F A279316 a(n) = a(n-7) for n > 6.
%F A279316 a(n) = A279313(2n)/2.
%F A279316 a(n) = -m*(m^5 - 21*m^4 + 160*m^3 - 525*m^2 + 739*m - 714)/360 where m = n mod 7. - _Luce ETIENNE_, Nov 18 2018
%p A279316 a:=n->[0, 1, 2, 3, 3, 2, 1][(n mod 7)+1]: seq(a(n), n=0..300);
%t A279316 CoefficientList[Series[x*(1 + 2*x + 3*x^2 + 3*x^3 + 2*x^4 + x^5)/(1 - x^7), {x, 0, 100}], x]
%t A279316 PadRight[{}, 120, {0, 1, 2, 3, 3, 2, 1}] (* _Vincenzo Librandi_, Dec 10 2016 *)
%o A279316 (Magma) &cat[[0, 1, 2, 3, 3, 2, 1]: n in [0..10]];
%Y A279316 Cf. A279313.
%Y A279316 Cf. A010876.
%K A279316 nonn,easy
%O A279316 0,3
%A A279316 _Wesley Ivan Hurt_, Dec 09 2016