OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (20,-137,358,-240)
FORMULA
a(n) = 256*8^n/21 -108*6^n/5 + 125*5^n/12 -1/140. - R. J. Mathar, Mar 11 2011
a(0)=1, a(1)=20, a(2)=263, a(3)=2878, a(n)=20*a(n-1)-137*a(n-2)+ 358*a(n-3)- 240*a(n-4). - Harvey P. Dale, Nov 04 2012
MATHEMATICA
CoefficientList[Series[1/((1-x)(1-5x)(1-6x)(1-8x)), {x, 0, 30}], x] (* or *) LinearRecurrence[{20, -137, 358, -240}, {1, 20, 263, 2878}, 30] (* Harvey P. Dale, Nov 04 2012 *)
PROG
(Magma) I:=[1, 20, 263, 2878]; [n le 4 select I[n] else 20*Self(n-1)-137*Self(n-2)+358*Self(n-3)-240*Self(n-4): n in [1..25]]; /* or */ m:=25; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x)*(1-5*x)*(1-6*x)*(1-8*x)))); // Vincenzo Librandi, Jul 12 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved