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 A010876 #37 Sep 08 2022 08:44:37
%S A010876 0,1,2,3,4,5,6,0,1,2,3,4,5,6,0,1,2,3,4,5,6,0,1,2,3,4,5,6,0,1,2,3,4,5,
%T A010876 6,0,1,2,3,4,5,6,0,1,2,3,4,5,6,0,1,2,3,4,5,6,0,1,2,3,4,5,6,0,1,2,3,4,
%U A010876 5,6,0,1,2,3,4,5,6,0,1,2,3,4,5,6,0,1,2,3
%N A010876 a(n) = n mod 7.
%H A010876 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,1).
%F A010876 Complex representation: a(n) = (1/7)*(1-r^n) * Sum_{1<=k<7} k * Product_{1<=m<7, m<>k} (1-r^(n-m)) where r=exp(2*pi/7*i) and i=sqrt(-1).
%F A010876 Trigonometric representation: a(n) = (64/7)^2*(sin(n*pi/7))^2*Sum_{1<=k<7} k*Product_{1<=m<7,m<>k} sin((n-m)*pi/7)^2.
%F A010876 G.f.: ( Sum_{1<=k<7} k*x^k ) / (1 - x^7).
%F A010876 G.f.: x*(6*x^7-7*x^6+1)/((1-x^7)*(1-x)^2). - _Hieronymus Fischer_, May 31 2007
%F A010876 a(n) = floor(41152/3333333*10^(n+1)) mod 10. - _Hieronymus Fischer_, Jan 03 2013
%F A010876 a(n) = floor(7625/274514*7^(n+1)) mod 7. - _Hieronymus Fischer_, Jan 04 2013
%o A010876 (Sage) [power_mod(n,7,7) for n in range(0, 81)] # _Zerinvary Lajos_, Nov 07 2009
%o A010876 (PARI) a(n)=n%7 \\ _Charles R Greathouse IV_, Dec 05 2011
%o A010876 (Magma) &cat [[0..6]^^20]; // _Bruno Berselli_, Jun 09 2016
%Y A010876 Partial sums: A130485.
%Y A010876 Other related sequences: A130481, A130482, A130483, A130484.
%K A010876 nonn,easy
%O A010876 0,3
%A A010876 _N. J. A. Sloane_
%E A010876 Formula section re-edited for better readability by _Hieronymus Fischer_, Dec 05 2011