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,-247,660).
FORMULA
a(n) = 25*5^n/42 -121*11^n/6 +144*12^n/7. - R. J. Mathar, Jun 30 2013
a(0)=1, a(1)=28, a(2)=537; for n>2, a(n) = 28*a(n-1) -247*a(n-2) +660*a(n-3). - Vincenzo Librandi, Jul 04 2013
a(n) = 23*a(n-1) -132*a(n-2) +5^n. - Vincenzo Librandi, Jul 04 2013
MATHEMATICA
CoefficientList[Series[1 / ((1 - 5 x) (1 - 11 x) (1 - 12 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 04 2013 *)
LinearRecurrence[{28, -247, 660}, {1, 28, 537}, 20] (* Harvey P. Dale, Dec 25 2013 *)
PROG
(Magma) m:=20; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-5*x)*(1-11*x)*(1-12*x)))); /* or */ I:=[1, 28, 537]; [n le 3 select I[n] else 28*Self(n-1)-247*Self(n-2)+660*Self(n-3): n in [1..20]]; // Vincenzo Librandi, Jul 04 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved