OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (23,-164,352).
FORMULA
a(n)= 11^(n+2)/21 -2*8^(n+1)/3 +4^(n+1)/7. - R. J. Mathar, Nov 11 2012
a(0)=1, a(1)=23, a(2)=365; for n>2, a(n) = 23*a(n-1) -164*a(n-2) +352*a(n-3). - Vincenzo Librandi, Jul 03 2013
a(n) = 19*a(n-1) -88*a(n-2) +4^n. - Vincenzo Librandi, Jul 03 2013
MATHEMATICA
CoefficientList[Series[1 / ((1 - 4 x) (1 - 8 x) (1 - 11 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 03 2013 *)
PROG
(Magma) m:=20; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-4*x)*(1-8*x)*(1-11*x)))); /* or */ I:=[1, 23, 365]; [n le 3 select I[n] else 23*Self(n-1)-164*Self(n-2)+352*Self(n-3): n in [1..20]]; // Vincenzo Librandi, Jul 03 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved