OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (28,-263,896,-660).
FORMULA
a(n)=(18*11^(n+3) - 25*10^(n+3) + 9*6^(n+3) - 2)/900. [Yahia Kahloune, Jun 27 2013]
a(0)=1, a(1)=28, a(2)=521, a(3)=8120; for n>3, a(n) = 28*a(n-1) -263*a(n-2) +896*a(n-3)-660*a(n-4). - Vincenzo Librandi, Jul 16 2013
MATHEMATICA
CoefficientList[Series[1 / ((1 - x) (1 - 6 x) (1 - 10 x) (1 - 11 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 16 2013 *)
LinearRecurrence[{28, -263, 896, -660}, {1, 28, 521, 8120}, 20] (* Harvey P. Dale, Mar 31 2018 *)
PROG
(Magma) m:=25; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x)*(1-6*x)*(1-10*x)*(1-11*x)))); /* or */ I:=[1, 28, 521, 8120]; [n le 4 select I[n] else 28*Self(n-1)-263*Self(n-2)+896*Self(n-3)-660*Self(n-4): n in [1..25]]; // Vincenzo Librandi, Jul 16 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved