OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (18,-111,262,-168).
FORMULA
G.f.: 1/((1-x)*(1-4*x)*(1-6*x)*(1-7*x)).
a(n) = -1/90 +2^(2n+5)/9 -2^(n+2)*3^(n+3)/5 +7^(n+3)/18. [Bruno Berselli, May 08 2013]
a(0)=1, a(1)=18, a(2)=213, a(3)=2098, a(n)=18*a(n-1)-111*a(n-2)+ 262*a(n-3)- 168*a(n-4). - Harvey P. Dale, May 28 2015
MATHEMATICA
CoefficientList[Series[1/((1 - x) (1 - 4 x) (1 - 6 x) (1 - 7 x)), {x, 0, 20}], x] (* Bruno Berselli, May 08 2013 *)
LinearRecurrence[{18, -111, 262, -168}, {1, 18, 213, 2098}, 30] (* Harvey P. Dale, May 28 2015 *)
PROG
(PARI) Vec(1/((1-x)*(1-4*x)*(1-6*x)*(1-7*x))+O(x^20)) \\ Bruno Berselli, May 08 2013
(Magma) m:=20; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x)*(1-4*x)*(1-6*x)*(1-7*x)))); // Bruno Berselli, May 08 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved