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 A038740 #16 Aug 27 2025 03:56:43
%S A038740 1,9,47,188,643,1993,5798,16193,44068,118013,312974,825277,2169045,
%T A038740 5690426,14913861,39066661,102306471,267879086,701364436,1836256726,
%U A038740 4807458872,12586185670,32951178868,86267449214,225851287529
%N A038740 a(n) = T(n,n-3), array T as in A038738.
%H A038740 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (9,-34,71,-90,71,-34,9,-1).
%F A038740 G.f.: x^3/((1-3*x+x^2)*(1-x)^6).
%F A038740 a(3)=1, a(4)=9, a(5)=47, a(6)=188, a(7)=643, a(8)=1993, a(9)=5798, a(10)=16193, a(n) = 9*a(n-1)-34*a(n-2)+71*a(n-3)-90*a(n-4)+71*a(n-5)-34*a(n-6)+9*a(n-7)-a(n-8). - _Harvey P. Dale_, Jan 06 2012
%t A038740 Drop[CoefficientList[Series[x^3/((1-3x+x^2)(1-x)^6),{x,0,30}],x],3] (* or *) LinearRecurrence[ {9,-34,71,-90,71,-34,9,-1},{1,9,47,188,643,1993,5798,16193},30] (* _Harvey P. Dale_, Jan 06 2012 *)
%Y A038740 Cf. A038738.
%K A038740 nonn,easy,changed
%O A038740 3,2
%A A038740 _Clark Kimberling_, May 02 2000