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 A140342 #13 Jul 31 2015 21:32:32
%S A140342 0,0,0,0,0,1,5,14,28,42,42,0,-131,-417,-924,-1652,-2380,-2380,0,7753,
%T A140342 25213,56714,102256,147798,147798,0,-479779,-1557649,-3499720,
%U A140342 -6305992,-9112264,-9112264,0,29587889,96072133,215873462,388991876,562110290,562110290,0
%N A140342 a(n)=5a(n-1)-11a(n-2)+13a(n-3)-9a(n-4)+3a(n-5)-a(n-6).
%C A140342 This is the main sequence representing the degenerate case of sequences which equal their seventh difference, where besides the generic a(n)=7a(n-1)-21(n-2)+35a(n-3)-35a(n-4)+21a(n-5)-7a(n-6)+2a(n-7), cf. A135356, there is also a shorter recurrence.
%C A140342 After the first four terms, every seventh term is zero. - _Harvey P. Dale_, Sep 20 2012
%H A140342 Harvey P. Dale, <a href="/A140342/b140342.txt">Table of n, a(n) for n = 0..1000</a>
%H A140342 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (5, -11, 13, -9, 3, -1).
%F A140342 O.g.f.: x^5/(1-5x+11x^2-13x^3+9x^4-3x^5+x^6). - _R. J. Mathar_, Jul 10 2008
%t A140342 LinearRecurrence[{5,-11,13,-9,3,-1},{0,0,0,0,0,1},40] (* _Harvey P. Dale_, Sep 20 2012 *)
%Y A140342 Cf. A135356, A140343.
%K A140342 sign,easy
%O A140342 0,7
%A A140342 _Paul Curtz_, May 29 2008
%E A140342 Edited and extended by _R. J. Mathar_, Jul 10 2008