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) = 4*A187709(n).
a(n) = 9*a(n-1) - 4 for n > 0.
a(n) = 10*a(n-1) - 9*a(n-2) for n > 1.
G.f.: 4*(1-2*x)/((1-x)*(1-9*x)).
From Elmo R. Oliveira, Aug 23 2024: (Start)
E.g.f.: exp(x)*(7*exp(8*x) + 1)/2.
a(n) = A199567(n)/2. (End)
MATHEMATICA
(7*9^Range[0, 20]+1)/2 (* or *) LinearRecurrence[{10, -9}, {4, 32}, 20] (* Harvey P. Dale, Dec 08 2012 *)
PROG
(Magma) [(7*9^n+1)/2: n in [0..30]];
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Nov 08 2011
STATUS
approved