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 A089985 #15 Jul 03 2023 08:55:17
%S A089985 2,3,6,10,18,34,66,130,258,514,1026,2050,4098,8194,16386,32770,65538,
%T A089985 131074,262146,524290,1048578,2097154,4194306,8388610,16777218,
%U A089985 33554434,67108866,134217730,268435458,536870914,1073741826,2147483650
%N A089985 a(n) = A089709(n+1)/A089709(n).
%H A089985 Vincenzo Librandi, <a href="/A089985/b089985.txt">Table of n, a(n) for n = 1..2000</a>
%H A089985 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (3, -2).
%F A089985 a(n) = 2^(n-1)+2, n>2.
%t A089985 Join[{2,3},Rest[2^Range[40]+2]] (* _Harvey P. Dale_, Sep 19 2011 *)
%Y A089985 Cf. A089709.
%Y A089985 Essentially the same as A056469.
%K A089985 nonn,easy
%O A089985 1,1
%A A089985 _Ray Chandler_, Nov 21 2003