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 A094038 #11 Jan 01 2016 19:35:11
%S A094038 0,1,2,8,24,84,280,960,3264,11152,38048,129920,443520,1514304,5170048,
%T A094038 17651712,60266496,205762816,702517760,2398545920,8189147136,
%U A094038 27959497728,95459694592,325919784960,1112759746560,3799199420416
%N A094038 Binomial transform of (Pell(-n)+Pell(n))/2.
%C A094038 Also binomial transform of Pell(n)(1-(-1)^n)/2.
%C A094038 a(n+2) = A088013(n+1) + A007070(n) - _Creighton Dement_, Oct 23 2004
%H A094038 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,0,-8,4).
%F A094038 G.f.: x(1-2x)/((1-2x^2)(1-4x+2x^2));
%F A094038 a(n)=(sqrt(2)/8)((2+sqrt(2))^n-(2-sqrt(2))^n+(sqrt(2))^n-(-sqrt(2))^n).
%t A094038 LinearRecurrence[{4,0,-8,4},{0,1,2,8},30] (* _Harvey P. Dale_, Jan 01 2016 *)
%Y A094038 Cf. A000129, A094039, A051450.
%K A094038 easy,nonn
%O A094038 0,3
%A A094038 _Paul Barry_, Apr 23 2004