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 A131036 #15 Jan 01 2024 23:48:32
%S A131036 1,1,3,-3,7,-9,9,-1,-3,3,-7,-1,1,1,3,-3,7,-9,9,-1,-3,3,-7,-1,1,1,3,-3,
%T A131036 7,-9,9,-1,-3,3,-7,-1,1,1,3,-3,7,-9,9,-1,-3,3,-7,-1
%N A131036 First differences of A131711.
%C A131036 The equivalent operation on A001333 yields last digits A131707 and their first differences A131715.
%H A131036 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (-1,0,0,-1,-1,0,0,-1,-1).
%F A131036 a(n) = a(n-12).
%F A131036 From _Chai Wah Wu_, Jan 09 2021: (Start)
%F A131036 a(n) = - a(n-1) - a(n-4) - a(n-5) - a(n-8) - a(n-9) for n > 8.
%F A131036 G.f.: (x^8 + 8*x^7 + 4*x^6 + 5*x^4 + 4*x^2 + 2*x + 1)/(x^9 + x^8 + x^5 + x^4 + x + 1). (End)
%t A131036 Differences[PadRight[{},120,{0,1,2,5,2,9,0,9,8,5,8,1}]] (* _Harvey P. Dale_, Dec 29 2014 *)
%Y A131036 Cf. A131711.
%K A131036 sign
%O A131036 0,3
%A A131036 _Paul Curtz_, Sep 23 2007
%E A131036 Edited by _R. J. Mathar_, Jul 07 2008