OFFSET
0,3
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (9,-15,7).
FORMULA
a(n) = 9*a(n-1) - 15*a(n-2) + 7*a(n-3) for n > 2.
G.f.: (1 - 9*x + 50*x^2)/((1 - 7*x)*(1 -x)^2). - Vincenzo Librandi, Jan 04 2013
E.g.f.: exp(x)*(exp(6*x) - 7*x). - Elmo R. Oliveira, Sep 10 2024
MATHEMATICA
CoefficientList[Series[(1 - 9*x + 50*x^2)/((1 - 7*x)*(1 -x)^2), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 04 2013 *)
PROG
(Magma) [7^n-7*n: n in [0..25]];
(PARI) a(n)=7^n-7*n \\ Charles R Greathouse IV, Jul 06 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Oct 26 2011
STATUS
approved