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a(n) = 3*n^3 + 2*n^2 + n.
3

%I #22 Sep 08 2022 08:45:05

%S 0,6,34,102,228,430,726,1134,1672,2358,3210,4246,5484,6942,8638,10590,

%T 12816,15334,18162,21318,24820,28686,32934,37582,42648,48150,54106,

%U 60534,67452,74878,82830,91326,100384,110022,120258,131110,142596

%N a(n) = 3*n^3 + 2*n^2 + n.

%H Vincenzo Librandi, <a href="/A067389/b067389.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1).

%F a(n) = n*A056109(n) = A045991(n+1)+A033431(n). - _Henry Bottomley_, Jan 25 2002

%F From _Chai Wah Wu_, Apr 25 2017: (Start)

%F a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n > 3.

%F G.f.: 2*x*(x^2 + 5*x + 3)/(x - 1)^4. (End)

%p a:=n->n+2*n^2+3*n^3: seq(a(n), n=0..36); # _Zerinvary Lajos_, Oct 05 2007

%t Table[3*n^3+2*n^2+n,{n,0,80}] (* _Vladimir Joseph Stephan Orlovsky_, May 07 2011 *)

%t LinearRecurrence[{4,-6,4,-1},{0,6,34,102},40] (* _Harvey P. Dale_, Oct 01 2019 *)

%o (Magma) [3*n^3 + 2*n^2 + n: n in [0..60]]; // _Vincenzo Librandi_, May 08 2011

%K nonn,easy

%O 0,2

%A _George E. Antoniou_, Jan 21 2002

%E More terms from _Henry Bottomley_, Jan 25 2002