OFFSET
0,2
COMMENTS
LINKS
Colin Barker, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (9,-20).
FORMULA
G.f.: (1-3*x)/((1-4*x)*(1-5*x)).
a(n) = 2*5^n - 4^n.
a(n) = 9*a(n-1) - 20*a(n-2) for n>1. - Colin Barker, Jun 25 2020
MATHEMATICA
CoefficientList[Series[(1-3x)/((1-4x)(1-5x)), {x, 0, 20}], x] (* or *) LinearRecurrence[{9, -20}, {1, 6}, 30] (* Harvey P. Dale, Jan 07 2022 *)
PROG
(PARI) Vec((1 - 3*x) / ((1 - 4*x)*(1 - 5*x)) + O(x^25)) \\ Colin Barker, Jun 25 2020
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Jun 24 2003
STATUS
approved