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 A156551 #18 Dec 12 2023 08:03:44 %S A156551 8,6,0,4,2,2,4,0,6,8,8,6,0,4,2,2,4,0,6,8,8,6,0,4,2,2,4,0,6,8,8,6,0,4, %T A156551 2,2,4,0,6,8,8,6,0,4,2,2,4,0,6,8,8,6,0,4,2,2,4,0,6,8,8,6,0,4,2,2,4,0, %U A156551 6,8,8,6,0,4,2,2,4,0,6,8,8,6,0,4,2,2,4,0,6,8 %N A156551 Period 10: repeat [8,6,0,4,2,2,4,0,6,8]. %C A156551 See A131715. %F A156551 a(n) = A155110(n) mod 10. %F A156551 G.f.: 2*(4*x^8-x^7+x^6+x^5+x^3+x^2-x+4)/((1-x)*(x^4-x^3+x^2-x+1)*(x^4+x^3+x^2+x+1)). - _R. J. Mathar_, Feb 23 2009 %F A156551 a(n) = (15*(4-m^4+8*m^3-19*m^2+12*m)-2*(m^3-6*m^2+17*m-18)*(-1)^floor(n/5))/12 where m = n-5*floor(n/5). - _Luce ETIENNE_, Oct 13 2017 %Y A156551 Cf. A010874, A131715, A155110. %K A156551 nonn,easy,less %O A156551 0,1 %A A156551 _Paul Curtz_, Feb 09 2009 %E A156551 Edited by _R. J. Mathar_, Feb 23 2009 %E A156551 More terms from _Jinyuan Wang_, Feb 26 2020