A014937 - OEIS

%I #15 Feb 12 2024 06:36:37

%S 1,41,1241,33241,833241,20033241,468033241,10708033241,241108033241,

%T 5361108033241,118001108033241,2575601108033241,55823601108033241,

%U 1202703601108033241,25778703601108033241,550066703601108033241

%N a(1)=1, a(n)=n*20^(n-1)+a(n-1).

%H Harvey P. Dale, <a href="/A014937/b014937.txt">Table of n, a(n) for n = 1..750</a>

%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (41, -440, 400).

%F a(1)=1, a(2)=41, a(3)=1241, a(n)=41*a(n-1)-440*a(n-2)+400*a(n-3) From _Harvey P. Dale_, Jun 04 2012

%F G.f.:  -x / ( (x-1)*(-1+20*x)^2 ). - _R. J. Mathar_, Nov 07 2015

%t RecurrenceTable[{a[1]==1,a[n]==n*20^(n-1)+a[n-1]},a,{n,20}] (* or *) LinearRecurrence[{41,-440,400},{1,41,1241},20] (* _Harvey P. Dale_, Jun 04 2012 *)

%K nonn,easy

%O 1,2

%A _Olivier Gérard_