login
A064755
a(n) = n*9^n - 1.
6
8, 161, 2186, 26243, 295244, 3188645, 33480782, 344373767, 3486784400, 34867844009, 345191655698, 3389154437771, 33044255768276, 320275094369453, 3088366981419734, 29648323021629455, 283512088894331672, 2701703435345984177
OFFSET
1,1
FORMULA
From Chai Wah Wu, Feb 01 2018: (Start)
a(n) = 19*a(n-1) - 99*a(n-2) + 81*a(n-3) for n > 3.
G.f.: x*(81*x^2 - 9*x - 8)/((x - 1)*(9*x - 1)^2). (End)
MATHEMATICA
Table[n*9^n-1, {n, 20}] (* Harvey P. Dale, Feb 28 2017 *)
PROG
(Magma) [ n*9^n-1: n in [1..20]]; // Vincenzo Librandi, Sep 16 2011
CROSSREFS
Sequence in context: A300466 A184605 A195607 * A140337 A245322 A305524
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Oct 19 2001
STATUS
approved