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 A083085 #24 Feb 24 2024 04:31:19
%S A083085 1,-1,9,-41,209,-1041,5209,-26041,130209,-651041,3255209,-16276041,
%T A083085 81380209,-406901041,2034505209,-10172526041,50862630209,
%U A083085 -254313151041,1271565755209,-6357828776041,31789143880209,-158945719401041,794728597005209,-3973642985026041
%N A083085 a(n) = (2+(-5)^n)/3.
%C A083085 Inverse binomial transform of A083086.
%H A083085 Vincenzo Librandi, <a href="/A083085/b083085.txt">Table of n, a(n) for n = 0..300</a>
%H A083085 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (-4,5).
%F A083085 a(n) = (2+(-5)^n)/3.
%F A083085 G.f.: (1+3*x)/((1+5*x)*(1-x)).
%F A083085 E.g.f.: (2*exp(x)+exp(-5*x))/3.
%F A083085 a(n) = -5*a(n-1) + 4. - _Vincenzo Librandi_, Nov 12 2011
%p A083085 A083085:=n->(2+(-5)^n)/3: seq(A083085(n), n=0..30); # _Wesley Ivan Hurt_, Nov 02 2014
%t A083085 Table[(2 + (-5)^n)/3, {n, 0, 30}] (* _Wesley Ivan Hurt_, Nov 02 2014 *)
%o A083085 (Magma) [(2+(-5)^n)/3: n in [0..30]]; // _Vincenzo Librandi_, Nov 12 2011
%Y A083085 Cf. A083086.
%K A083085 easy,sign
%O A083085 0,3
%A A083085 _Paul Barry_, Apr 23 2003