OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (22,-149,308,-180)
FORMULA
a(n) = (7*10^(n+3) - 9^(n+4) + 9*2^(n+3) - 7)/504. - Yahia Kahloune, Jul 08 2013
a(0)=1, a(1)=22, a(2)=335, a(3)=4400; for n>3, a(n) = 22*a(n-1) -149*a(n-2) +308*a(n-3) -180*a(n-4). - Vincenzo Librandi, Jul 08 2013
a(0)=1, a(1)=22; for n>1 a(n) = 19*a(n-1) -90*a(n-2) +2^n -1. - Vincenzo Librandi, Jul 08 2013
MATHEMATICA
CoefficientList[Series[1 / ((1 - x) (1 - 2 x) (1 - 9 x) (1 - 10 x)), {x, 0, 20}], x] (* Vincenzo Librandi Jul 08 2013 *)
PROG
(Magma) I:=[1, 22, 335, 4400]; [n le 4 select I[n] else 22*Self(n-1)-149*Self(n-2)+308*Self(n-3)-180*Self(n-4): n in [1..25]]; /* or */ m:=25; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x)*(1-2*x)*(1-9*x)*(1-10*x)))); // Vincenzo Librandi, Jul 08 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved