A038865 - OEIS

%I #11 Jun 17 2017 00:25:51

%S 63,117,189,279,387,513,657,819,999,1197,1413,1647,1899,2169,2457,

%T 2763,3087,3429,3789,4167,4563,4977,5409,5859,6327,6813,7317,7839,

%U 8379,8937,9513,10107,10719,11349,11997,12663,13347,14049,14769,15507,16263

%N (n+3)^3 - n^3.

%H Harvey P. Dale, <a href="/A038865/b038865.txt">Table of n, a(n) for n = 1..1000</a>

%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3, -3, 1).

%F G.f.: -((9*(3*x^2-8*x+7))/(x-1)^3). - _Harvey P. Dale_, Mar 04 2014

%F a(1)=63, a(2)=117, a(3)=189, a(n)=3*a(n-1)-3*a(n-2)+a(n-3). - _Harvey P. Dale_, Mar 04 2014

%t Table[(n+3)^3-n^3,{n,50}] (* or *) LinearRecurrence[{3,-3,1},{63,117,189},50] (* _Harvey P. Dale_, Mar 04 2014 *)

%o (PARI) a(n)=(n+3)^3-n^3 \\ _Charles R Greathouse IV_, Jun 17 2017

%K nonn,easy

%O 1,1

%A _Jeff Burch_