A014903 - OEIS

%I #26 Feb 19 2024 01:52:36

%S 1,21,402,7642,145203,2758863,52418404,995949684,18923044005,

%T 359537836105,6831218886006,129793158834126,2466070017848407,

%U 46855330339119747,890251276443275208,16914774252422228968,321380710796022350409,6106233505124424657789

%N a(1)=1, a(n) = 19*a(n-1) + n.

%H Vincenzo Librandi, <a href="/A014903/b014903.txt">Table of n, a(n) for n = 1..200</a>

%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (21, -39, 19).

%F a(1)=1, a(2)=21, a(3)=402, a(n) = 21*a(n-1) - 39*a(n-2) + 19*a(n-3). - _Vincenzo Librandi_, Oct 20 2012

%t LinearRecurrence[{21, -39, 19}, {1, 21, 402}, 20] (* _Vincenzo Librandi_, Oct 20 2012 *)

%o (Magma) I:=[1, 21, 402]; [n le 3 select I[n] else 21*Self(n-1) - 39*Self(n-2) + 19*Self(n-3): n in [1..20]]; // _Vincenzo Librandi_, Oct 20 2012

%K nonn

%O 1,2

%A _N. J. A. Sloane_, _Olivier Gérard_