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 A084850 #9 Mar 15 2016 23:00:23
%S A084850 1,5,20,68,208,592,1600,4160,10496,25856,62464,148480,348160,806912,
%T A084850 1851392,4210688,9502720,21299200,47448064,105119744,231735296,
%U A084850 508559360,1111490560,2420113408,5251268608,11358175232,24494735360
%N A084850 2^(n-1)*(n^2+2n+2).
%C A084850 Binomial transform of A084849. a(n)=A014477(n-1)+A001787(n+1).
%H A084850 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (6,-12,8).
%F A084850 G.f.: (1 - x+2x^2)/(1 - 2x)^3.
%F A084850 Equals A134083 * [1,2,3,...]. - _Gary W. Adamson_, Oct 07 2007
%t A084850 LinearRecurrence[{6,-12,8},{1,5,20},40] (* _Harvey P. Dale_, Mar 15 2016 *)
%Y A084850 Cf. A134083.
%K A084850 easy,nonn
%O A084850 0,2
%A A084850 _Paul Barry_, Jun 09 2003