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 A084859 #10 Jun 13 2015 00:51:05
%S A084859 1,4,16,62,232,842,2980,10334,35248,118610,394684,1301126,4255624,
%T A084859 13825658,44657428,143521838,459230560,1463719586,4649308012,
%U A084859 14722502870,46491507256,146447041994,460259735236,1443537130622
%N A084859 Binomial transform of Cullen numbers A002064.
%H A084859 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (8,-21,18).
%F A084859 a(n)=2^n+2n*3^(n-1); a(n)=sum{k=0..n, C(n, k)(1+k*2^k) }.
%F A084859 O.g.f.: (1-4x+5x^2)/[(1-2x)(-1+3x)^2]. - _R. J. Mathar_, Apr 02 2008
%F A084859 a(0)=1, a(1)=4, a(2)=16, a(n)=8*a(n-1)-21*a(n-2)+18*a(n-3). - _Harvey P. Dale_, Mar 31 2015
%t A084859 LinearRecurrence[{8,-21,18},{1,4,16},30] (* _Harvey P. Dale_, Mar 31 2015 *)
%Y A084859 Cf. A004277.
%K A084859 easy,nonn
%O A084859 0,2
%A A084859 _Paul Barry_, Jun 12 2003