# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/

Search: id:a128985
Showing 1-1 of 1

%I A128985 #21 Sep 08 2022 08:45:30
%S A128985 0,16,144,768,3200,11520,37632,114688,331776,921600,2478080,6488064,
%T A128985 16613376,41746432,103219200,251658240,606076928,1443889152,
%U A128985 3406823424,7969177600,18496880640,42630905856,97626619904,222264557568
%N A128985 a(n) = (n^3 - n^2)*2^n.
%H A128985 Vincenzo Librandi, <a href="/A128985/b128985.txt">Table of n, a(n) for n = 1..1000</a>
%H A128985 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (8,-24,32,-16).
%F A128985 G.f.: 16*x^2*(1 + x)/(1 - 2*x)^4. - _Vincenzo Librandi_, Feb 11 2013
%F A128985 a(n) = 8*a(n-1) -24*a(n-2) +32*a(n-3) -16*a(n-4). - _Vincenzo Librandi_, Feb 11 2013
%t A128985 CoefficientList[Series[16 x (1+x)/(1 - 2 x)^4, {x, 0, 30}], x] (* _Vincenzo Librandi_, Feb 11 2013 *)
%t A128985 Table[(n^3-n^2)2^n,{n,30}] (* or *) LinearRecurrence[{8,-24,32,-16},{0,16,144,768},30] (* _Harvey P. Dale_, Jul 06 2014  *)
%o A128985 (Magma) [(n^3-n^2)*2^n: n in [0..25]]; (* or *) I:=[0, 16, 144, 768]; [n le 4 select I[n] else 8*Self(n-1) - 24*Self(n-2) + 32*Self(n-3) - 16*Self(n-4): n in [1..25]]; // _Vincenzo Librandi_, Feb 11 2013
%o A128985 (PARI) a(n)=(n^3-n^2)<<n \\ _Charles R Greathouse IV_, Oct 07 2015
%Y A128985 Cf. A128796, A036289.
%K A128985 nonn,easy
%O A128985 1,2
%A A128985 _Mohammad K. Azarian_, Apr 30 2007
%E A128985 Offset corrected by _Mohammad K. Azarian_, Nov 19 2008

# Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE