OFFSET
1,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (9,0,1,-9)
FORMULA
a(n) = +9*a(n-1) +a(n-3) -9*a(n-4). G.f.: x / ( (x-1)*(9*x-1)*(1+x+x^2) ). - R. J. Mathar, Jan 08 2011
a(n) = floor((81/728)*9^n). - Tani Akinari, Jul 18 2014
EXAMPLE
The first six terms have base 9 representations 1, 10, 100, 1001, 10010, 100100.
MATHEMATICA
Table[FromDigits[PadRight[{}, n, {1, 0, 0}], 9], {n, 30}] (* Harvey P. Dale, Dec 18 2018 *)
PROG
(PARI) Vec(x / ( (x-1)*(9*x-1)*(1+x+x^2) )+ O(x^30)) \\ Michel Marcus, Jul 18 2014
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
EXTENSIONS
More terms from Michel Marcus, Jul 18 2014
STATUS
approved