A014914 - OEIS

%I #28 Feb 19 2024 01:53:20

%S 1,27,678,16954,423855,10596381,264909532,6622738308,165568457709,

%T 4139211442735,103480286068386,2587007151709662,64675178792741563,

%U 1616879469818539089,40421986745463477240,1010549668636586931016

%N a(1)=1, a(n) = 25*a(n-1) + n.

%H Vincenzo Librandi, <a href="/A014914/b014914.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 (27, -51, 25).

%F a(1)=1, a(2)=27, a(3)=678, a(n) = 27*a(n-1) - 51*a(n-2) + 25*a(n-3). - _Vincenzo Librandi_, Oct 19 2012

%t LinearRecurrence[{27, -51, 25}, {1, 27, 678}, 20] (* _Vincenzo Librandi_, Oct 19 2012 *)

%t nxt[{n_,a_}]:={n+1,25a+n+1}; NestList[nxt,{1,1},20][[All,2]] (* _Harvey P. Dale_, Nov 16 2021 *)

%o (Magma) I:=[1, 27, 678]; [n le 3 select I[n] else 27*Self(n-1) - 51*Self(n-2)+ 25*Self(n-3): n in [1..20]]; // _Vincenzo Librandi_, Oct 19 2012

%K nonn

%O 1,2

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