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%I #23 Sep 08 2022 08:45:26
%S 0,6,15,34,85,236,695,2094,6345,19216,58075,175154,527405,1586196,
%T 4766655,14316214,42981265,129009176,387158435,1161737274,3485735925,
%U 10458256156,31376865415,94134790334,282412759385,847255055136
%N 5n+3^n-2^n.
%H Vincenzo Librandi, <a href="/A120849/b120849.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (7,-17,17,-6).
%F G.f.: x*(6-27*x+31*x^2)/((1-2*x)*(1-3*x)*(1-x)^2). - _Vincenzo Librandi_, Feb 24 2013
%F a(n) = 7*a(n-1)-17*a(n-2)+17*a(n-3)-6*a(n-4). - _Vincenzo Librandi_, Feb 24 2013
%t CoefficientList[Series[x (6 - 27 x + 31 x^2)/((1-2 x) (1-3 x) (1 - x)^2), {x, 0, 30}], x] (* _Vincenzo Librandi_, Feb 24 2013 *)
%o (Magma) [5*n+3^n-2^n: n in [0..30]] /* or */ I:=[0,6,15,34]; [n le 4 select I[n] else 7*Self(n-1)-17*Self(n-2)+17*Self(n-3)-6*Self(n-4): n in [1..30]]; // _Vincenzo Librandi_, Feb 24 2013
%Y Cf. A001047, A007689.
%K nonn,easy
%O 0,2
%A _Mohammad K. Azarian_, Aug 18 2006
%E Edited by _Ray Chandler_, Sep 06 2006
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