%I #33 Aug 18 2018 17:36:51
%S -1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,
%T 25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,
%U 48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73
%N a(n) = n - 1.
%H Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a>
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2, -1).
%F a(n) = 2*a(n-1) -a(n-2). G.f.: (-1+2*x)/(x-1)^2. - _R. J. Mathar_, Feb 11 2010
%t Range[0,80]-1 (* _Harvey P. Dale_, Apr 05 2012 *)
%t LinearRecurrence[{2,-1},{-1,0},75] (* _Ray Chandler_, Jul 30 2015 *)
%o (PARI) a(n)=n-1 \\ _Charles R Greathouse IV_, Aug 26 2011
%Y Cf. A000027, A023444, ..., A023482, A022958, ..., A022996, A256958.
%K sign,easy
%O 0,4
%A _N. J. A. Sloane_.