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 A010711 #26 Jul 08 2025 01:44:52 %S A010711 4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6, %T A010711 4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6,4,6, %U A010711 4,6,4,6,4,6,4,6,4,6,4,6,4 %N A010711 Period 2: repeat (4,6). %H A010711 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (0,1). %F A010711 a(n)=-(-1)^n+5. _Paolo P. Lava_, Oct 20 2006 %F A010711 G.f.: -2*(2+3*x)/((x-1)*(1+x)). %F A010711 a(n) = 2*A010693(n). %o A010711 (PARI) a(n)=n%2*2+4 \\ _Charles R Greathouse IV_, Jun 11 2015 %K A010711 nonn,easy %O A010711 0,1 %A A010711 _N. J. A. Sloane_ %E A010711 First formula corrected by _Paolo P. Lava_, Mar 14 2011