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 A189740 #28 Aug 03 2015 12:24:05
%S A189740 1,2,3,4,8,15,28,53,102,196,377,726,1399,2696,5196,10015,19304,37209,
%T A189740 71722,138248,266481,513658,990107,1908492,3678736,7090991,13668324,
%U A189740 26346541,50784590,97890444,188689897,363711470,701076399,1351368208,2604845972
%N A189740 Partial sums of tetranacci numbers (A000288).
%H A189740 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (2, 0, 0, 0, -1).
%F A189740 a(1)=1, a(2)=2, a(3)=3, a(4)=4, a(5)=8, a(n)=2*a(n-1)-a(n-5). - _Harvey P. Dale_, May 23 2011
%F A189740 G.f.: -x*(2*x^3+x^2-1) / ((x-1)*(x^4+x^3+x^2+x-1)). - _Colin Barker_, Aug 07 2013
%t A189740 Accumulate[LinearRecurrence[{1,1,1,1},{1,1,1,1},50]] (* or *) LinearRecurrence[ {2,0,0,0,-1},{1,2,3,4,8},50] (* _Harvey P. Dale_, May 23 2011 *)
%Y A189740 Cf. A000288.
%K A189740 nonn,easy
%O A189740 1,2
%A A189740 _Harvey P. Dale_, May 23 2011