OFFSET
0,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients,signature (10,-9).
FORMULA
a(n) = 9*a(n-1)+4.
a(n) = 10*a(n-1)-9*a(n-2), n>1.
G.f.: (3 + x)/(1 - 10*x + 9*x^2). - Vincenzo Librandi, Jan 03 2013
From Elmo R. Oliveira, Aug 15 2024: (Start)
E.g.f.: exp(x)*(7*exp(8*x) - 1)/2.
a(n) = A198965(n)/2. (End)
MATHEMATICA
CoefficientList[Series[(3 + x)/(1 - 10 x + 9 x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 03 2013 *)
LinearRecurrence[{10, -9}, {3, 31}, 30] (* Harvey P. Dale, Oct 10 2017 *)
PROG
(Magma) [(7*9^n-1)/2: n in [0..20]];
(PARI) a(n)=7*9^n\2 \\ Charles R Greathouse IV, Oct 16 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Nov 01 2011
STATUS
approved